OphthalmologyTimes - Cataract Surgery Resource Center

Reviewed by Mohammad Soleimani, MD

Take-home message: A study comparing methods of optical correction after surgery for congenital cataract shows no difference in visual outcomes or myopic shift between children left aphakic and those who received piggyback IOL implantation. Piggyback IOL implantation during the first six months of life was associated with a higher rate of reoperations for complication management.

Tehran, Iran—Piggyback IOL implantation is an optically acceptable option for refractive correction after cataract surgery in infants.

However, the approach does not result in better visual outcomes compared with leaving the eye primarily aphakic and using other methods for optical correction.

Furthermore, when the cataract surgery is performed during the first six months of life, piggyback IOL implantation exposes the child to a higher incidence of reoperations for complication management, according to the results of a study conducted by Mohammad Soleimani, MD, assistant professor, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

“Optical correction after surgery for congenital cataract remains controversial. The sample size in our study was small and so it was not adequately powered to rule out a difference in visual outcomes between groups if it does exist,” Dr. Soleimani said. “Therefore, studies including a larger population are needed to confirm or reject our findings.”

Dr. Soleimani and colleagues at the Farabi Eye Hospital, Tehran University of Medical Sciences, undertook a comparative study to evaluate the long-term efficacy and safety of piggyback IOL implantation versus aphakia for infantile cataract.

It included infants operated on between 1998 and 2007. There were 23 eyes of 14 infants that received a piggyback IOL and 32 eyes of 20 infants left aphakic after the cataract surgery.

“The findings of our study do favor leaving the eye aphakic,” he said. “In practice, however, it is important to individualize the decision by taking into account parental compliance with contact lens wear or spectacles that is critical for a good visual outcome.”

In the piggyback IOL group, a permanent posterior IOL was implanted in the capsular bag at the time of cataract surgery and a second temporary IOL was placed in the ciliary sulcus with the plan to explant the sulcus IOL later in life to compensate for changing refraction. In the aphakic group, optical correction was provided with contact lenses, spectacles, or secondary IOL implantation.

Findings

The mean age at the time of cataract surgery was seven and a half months for the piggyback IOL group and six months for the aphakic group. The difference between groups was not statistically significant.

Mean follow-up in the piggyback IOL and aphakic groups was 6.2 years and 5.8 years, respectively, and at last follow-up median logMAR visual acuity in the piggyback IOL and aphakia groups was 0.85 and 0.89, respectively (p> 0.05).

“In further analyses we found a positive relationship between age at the time of surgery and visual acuity at last follow-up in the aphakic group but not in the piggyback IOL group,” Dr. Soleimani reported.

Mean myopic shift at one year after surgery was also similar in the piggyback IOL and aphakic groups with -5.28 and -5.10 D, respectively.

“Previous studies report a significantly greater myopic shift in pseudophakic versus aphakic eyes,” Dr. Soleimani said. “The lack of difference between groups in our study may be explained by the effect of the piggyback IOL pushing on the posterior lens.”

The safety review showed that the rate of reoperations due to complications was three-fold and significantly higher in the eyes that received a piggyback IOL than in the aphakic group (48% versus 16%).

However, when the analysis was restricted to children who underwent cataract surgery when they were older than six months, the rate of reoperations for complications was lower in both groups and no longer significantly different between groups.

Mohammad Soleimani, MD

E: soleimani_md@yahoo.com

This article was adapted from Dr. Soleimani’s presentation at the 2015 meeting of the American Society of Cataract and Refractive Surgery. An article reporting on the study is in press in the Middle East African Journal of Ophthalmology. Dr. Soleimani has no relevant financial interests to disclose.

Reviewed by Mitchell A. Jackson, MD

Take-home message: An experienced user describes the ease and outcomes of astigmatism correction using a proprietary femtosecond laser system.

Lake Villa, IL—Use of a proprietary femtosecond laser system (LENSAR Laser System, LENSAR) is making astigmatism correction easy, efficient, and more accurate, according to Mitchell A. Jackson, MD

A software upgrade introduced in 2015 (Streamline) enables wireless transmission of preoperative topography data and an infrared image of the undilated eye to the laser. Intraoperatively, iris registration automatically adjusts for cyclorotation, eliminating the need to mark the cornea.

Arcuate incision planning using the nomogram the surgeon programmed into the laser is completed at the touch of a button by selecting the “Surgeon’s Table” tab located on the LENSAR programming screen. The treatment is delivered accurately due to the iris registration, using the system’s software for marking the refractive steep corneal axis and placing precise astigmatic incisions (Intelligent Incisions).

“LENSAR with Streamline brings automation, customization, and precision to planning and execution of astigmatism correction, and it has allowed me to consistently deliver predictable outcomes,” said Dr. Jackson, founder and chief executive officer, JacksonEye, Lake Villa, IL.

Dr. Jackson explained the steps involved in performing astigmatic correction with the LENSAR femtosecond laser and provided tips to surgeons for optimizing success.

Currently, wireless integration with the laser is available only when using the Cassini Corneal Shape Analyzer (i-Optics), but compatibility with the OPD-Scan III (Marco Ophthalmics) is coming soon.

One advantage of the Cassini is that it measures total, posterior, and anterior corneal astigmatism, Dr. Jackson said. Although the LENSAR software currently only uses the anterior surface data for astigmatism planning, a future software upgrade will allow surgeons to choose between the anterior and total corneal astigmatism values.

Optimizing ocular surface condition

“That will be a nice option because we know from work by Doug Koch, MD, and colleagues that the amount of posterior corneal astigmatism can influence outcomes of our astigmatic correction procedures,” Dr. Jackson said. “Currently, in cases where I expect the posterior corneal astigmatism is impacting the total astigmatism, I will adjust my current built-in nomogram accordingly.”

Regardless of which system surgeons use to obtain their preoperative diagnostics information for astigmatic correction, Dr. Jackson emphasized the importance of optimizing the condition of the ocular surface to assure quality data.

“Garbage in, equals garbage out,” Dr. Jackson said, adding that he likes to look for agreement between measurements obtained with several different devices.

The Cassini also captures an undilated image of the iris that will be used intraoperatively for iris registration, and the software confirms its compatibility in terms of proper focus and absence of any lid obstruction.

“Eliminating the need for corneal ink markings to identify the steep axis is now possible with the iris registration capability of Streamline,” Dr. Jackson said.

The diagnostic information is used to guide built-in nomograms for astigmatic correction. Surgeons will need to choose a reliable nomogram from another source when they are first starting to perform femtosecond laser astigmatic incisions. Widely used options for the LENSAR are those developed by Dr. Jackson, Jonathan Solomon, MD, and Rob Weinstock, MD.

Using your own data

“Once the diagnostics data are imported, all the surgeon has to do is press a button and the laser does the rest. However, there is also the option to change any of the parameters on the fly,” Dr. Jackson said.

Over time, surgeons can tweak the nomogram using their own data. The software for the LENSAR helps with that task as well because it captures all of the information needed, he added.

“Trust the nomogram you start with for the first 50 eyes, and then when you decide to personalize it, change one variable at a time,” Dr. Jackson advised.

When creating their own nomogram, surgeons also need to calculate their average surgically-induced astigmatism for the right and left eyes. A program developed by Warren Hill, MD, is helpful in that regard (www.sia-calculator.com).

Dr. Jackson also highlighted the value of the LENSAR laser’s Scheimpflug imaging systems that allow for dynamic scanning of the cornea and give real-time pachymetric information at the time of femtosecond astigmatic incision creation.

“Corneal hydration is dynamic, and the cornea may become dessicated during the procedure. Astigmatic incisions are usually made at 90% depth, and if the placement is based on a single preoperative reading, the cuts can go too deep and perforate,” Dr. Jackson said. “With dynamic imaging, there is much less chance of perforation and an increased likelihood they will be made at the true intended depth.”

Postop

Once the incisions are made, Dr. Jackson said that he generally leaves them closed and has patients return after three to four weeks for evaluation of their refractive outcome. Then, with the patient sitting in an exam lane at the slit-lamp, he can titrate the astigmatic effect as needed by opening the incisions.

“It is easy to do with a Sinskey hook or similar microsurgical instrument,” he said.

As an exception, the astigmatic incisions are opened intraoperatively in cases where intraoperative aberrometry is used (ORA, Alcon) and can determine if additional deepening and/or lengthening of the astigmatic incisions are needed.

Using the LENSAR laser, Dr. Jackson said that many surgeons treat up to 1.5 D of corneal astigmatism. He, however, is stretching his upper limit to 1.7 D with these techniques.

With the added range and increased predictability compared with manual incisions, Dr. Jackson said he is now using the laser to correct astigmatism in more eyes where he otherwise would have implanted a toric IOL.

“This shift reduces overhead and so helps enhance my bottom line,” Dr. Jackson said.

Mitchell A. Jackson, MD

E: mjlaserdoc@msn.com

Dr. Jackson is a consultant for LENSAR, i-Optics, and Marco Ophthalmics.

The prevalence of acute primary angle-closure glaucoma (APACG) is declining in Scotland as cataract surgery becomes more common, researchers said.

“We propose that increasing rates of cataract surgery performed at an earlier age group in Scotland have played a significant role in reducing the rate of APACG by reducing the incidence of obstruction and the level of lens and papillary block mechanisms,” wrote Stewart N. Gillan from Ninewells Hospital and Medical School in Dundee, United Kingdom, and colleagues.

They published their finding in Ophthalmic Epidemiology.

The researchers defined APACG as iridotrabecular contact resulting in peripheral anterior synechiae and/or raised IOP, causing glaucomatous optic neuropathy.

They enumerated four possible mechanisms for the condition: pupil block, obstruction at the level of the iris and/or ciliary body (plateau iris), obstruction at the level of the lens, and obstruction posterior to the lens (aqueous misdirection syndrome).

Six risk factors they reported include: older age, female sex, hypermetropia, lenticular changes, use of pharmaceutical products, and East Asian ethnicity.

Despite predictions that the prevalence of APACG, a leading cause of blindness, is set to rise worldwide, some authors have reported a decline in certain countries.

To situate Scotland in this context, Gillan and his colleagues analyzed national data from the Information Services Division (ISD) Scotland, which includes all activity carried out across the 14 Scottish health boards, including National Health Service (NHS) patients treated in private hospitals. (None of the private Scottish hospitals have emergency ophthalmic facilities.)

They counted the number of NHS patients diagnosed principally as having APACG, the number who underwent YAG laser peripheral iridotomy, and the number who had cataract surgery as an inpatient or day case, from 1 April 1998 to 31 March 2012.

They found that the number of patients coded for APACG dropped 46.4%, from 46.7 per million to 25 per million, a statistically significant change (P< 0.005).

Meanwhile, the rate of cataract surgery went up 73.4%, from 354.2 per 100,000 to 615.2 per 100,000, which was also significant (P< 0.005).

In addition, the rate of peripheral iridotomy spiralled 116.3%, from 38.0 per million to 82.2 per million. Even more striking, this increase took place in the most recent period; peripheral iridotomy actually decreased by 48.2% from1998 to 2008, before rocketing back up by 317.% between 2008 and 2012.

How to explain the trends

What factors could explain these trends? During this period, the mid-year estimates of the Scottish population increased by 4.6% The Scottish population under 50 years of age remained stable during this period while the population 50 years and older rose from 1.7 million to 2.1 million.

From the work of others, Gillan and colleagues said cataract surgery is being performed more frequently and at a younger age in the United Kingdom.

The beginning of the study period paralleled the kickoff of the U.K. Department of Health “Action on Cataracts” project. This initiative is designed to improve access to care for patients in need of cataract surgery, and to reduce variations in waiting times for cataract surgery.

The increased efficiency of the patient pathway succeeded in “massively increasing surgical throughput,” Gillan and colleagues wrote.

However, increasing rates of cataract surgery may not provide the only explanation for the decline in APACG, they wrote.

Work done by the International Society for Geographical and Epidemiological Ophthalmology has tightened the definition and classification of APACG. The European Glaucoma Society and the American Academy of Ophthalmology have endorsed this narrower definition. As a result, clinicians may be using the diagnosis less often, creating the perception of a decline in cases.

As for the peripheral iridotomy rates, increasing cataract rates could explain the decline in the first decade of the study period.

The authors attributed the subsequent increase to the introduction of the new General Ophthalmic Services contract in Scotland in 2006, providing free eye care services by optometrists.

Mandatory examinations

The mandatory, comprehensive ocular examinations introduced through this initiative included an assessment of the fundus following pupil dilation. Optometrists assessed anterior chamber depth and angle width using a slit lamp. National training included workshops on anterior segment assessment and gonioscopy.

As an effect of this, optometrists may be referring more patients to hospital eye services with suspected narrow angles, the researchers speculated.

The number of glaucoma specialist consultants in Scotland doubled from 2006 to 2012, and patients were streamlined into specialist glaucoma clinics. This, too, could have contributed to greater awareness of narrow angle disease and a higher rate of prophylactic iridotomy.

These findings in Scotland mostly parallel trends reported in England over the same time period, the researchers wrote. In the English study, overall PACG rates increased while acute angle-closure episodes decreased.

The authors speculated that the discrepancy might be attributable to the coding system in Scotland, which does not capture asymptomatic or chronic PACG that is managed in an outpatient clinic. They also said that not including these patients would not entirely account for the trends they documented.

Take-home message: An analysis including almost 3,000 eyes operated on with modern femtosecond laser technology found an anterior capsule tear rate of <0.1%.

By Cheryl Guttman Krader; Reviewed by Tim Roberts, MD

Sydney—Significant evidence in the literature shows that use of a femtosecond laser consistently creates a capsulotomy with precise geometry, circularity, and sizing.

Now, data from large studies also establish that the laser procedure is associated with a very low rate of anterior capsule tears, said Tim Roberts, MD.

“These are important points because the quality of the anterior capsulotomy is crucial to the safety and refractive outcome of cataract surgery,” said Dr. Roberts, consultant ophthalmic surgeon and clinical senior lecturer, University of Sydney and medical director, Vision Eye Institute Australia.

Dr. Roberts and colleagues at the Vision Eye Institute, Chatswood, reported their experience using a femtosecond laser platform (LenSx, Alcon Laboratories). In their prospective, consecutive series of 3,842 eyes, 7 eyes (0.18%) were identified as having a break in the anterior capsule rim.

However, further analyses showed the rate dropped significantly to 0.08% when the new soft contact lens patient interface (SoftFit) replaced the original rigid curved interface (0.08%, 2/3108 eyes versus 0.68%, 5/734 eyes, p = 0.004).

Dr. Roberts emphasized that the eyes in his group’s series was a consecutive cohort and included complex cases that may be at increased risk for anterior capsule tear—e.g., eyes with floppy iris syndrome, white cataract, pseudoexfoliation, and traumatic zonulopathy.

Putting it into perspective

Reviewing the literature on this topic, Dr. Roberts cited a recent paper that similarly reported a very low anterior capsule tear rate of 0.1% when analyzing outcomes for 1,000 eyes operated on at Moorfields Eye Hospital, London, using another femtosecond laser (Catalys, Abbott Medical Optics) [Day AC, et al. J Cataract Refract Surg. 2014;40:2031-2034].

In contrast, an earlier study using the Catalys system reported a high rate of 1.8% in 804 eyes [Abell et al. Ophthalmology. 2014;121:17-24].

Dr. Roberts said that the latter paper stirred controversy about femtosecond laser capsulotomy by hypothesizing that treating the capsule with a laser—irrespective of the platform used—may produce a germinative defect, rendering the capsule intrinsically weak.

“The high complication rate in the paper by Abell et al. focused attention on laser settings and surgical techniques used in laser cataract surgery,” he said. “There is no doubt that there will be ultrastructural differences in the capsule when the capsulotomy is created with a laser versus manually, but the important question is: From an evidence-based perspective, what, if any, are the clinical implications of these differences?”

When looking at the most recent published results of nearly 5,000 consecutive laser procedures from their group [Roberts et al. J Cataract Refract Surg. 2015;41:1109-1110] and the Moorfields group, using different laser systems, surgeons can now be confident that optimal laser settings and appropriate surgical technique will result in a perfectly circular, evenly sized and intact capsulotomy in nearly every case, Dr. Roberts noted.

He added that the advanced new patient interface for the femtosecond laser platform and refinement of laser settings and surgical technique over time have been “game changers” for achieving free-floating capsulotomies with an extremely low rate of anterior capsule tear.

Tim Roberts, MD

E: tim.roberts@visioneyeinstitute.com.au

This article was adapted from Dr. Roberts’ presentation at the 2015 meeting of the American Academy of Ophthalmology. Dr. Roberts is or has been a consultant to Abbott Medical Optics, Alcon Laboratories, Allergan, Bausch + Lomb, Device Technologies, and Pfizer.

Take-home message: Steven Dewey, MD, shares his experience with a recent patient case when a lens rotated. The leading possibility for why this may have happened is the lens was not stable in the bag.

By Steven Dewey, MD, Special to Ophthalmology Times

Colorado Springs, CO—A few months ago, I performed femtosecond laser-assisted cataract surgery on the left eye of a 67-year-old female patient, and implanted a toric lens (SN6AT9, Alcon Laboratories). Surgery was uneventful and the IOL was nicely aligned at the close of the case.

On the second day, the patient had a spike in IOP. I tapped the sideport incision to relieve pressure and placed the patient on brimonidine tartrate/timolol maleate (Combigan, Allergan) twice a day.

A few days later, closing in on the 1-week mark, she complained of blur. Ray tracing showed the IOL had rotated 69˚ counterclockwise (Figure 1).

Her refraction was now +2.75 -8.34 x 33. I wanted to give the capsular bag a chance to contract so we waited another 2 weeks to reposition the lens. At that point, the lens was easily rotated back into position and was perfectly aligned when I closed the eye, just as it had been at the initial surgery. This time I put the patient on Combigan and oral Diamox for 1 week as a preventive measure and she did not have an IOP spike.

However, she returned 2 weeks later with the same symptoms of blur: The lens had rotated out of position a second time, clockwise again, but this time only 44˚. This time, partly due to the patient’s schedule, we waited another 2 months for the repositioning. I found the lens was still surprisingly mobile in the bag, with less fibrosis than expected.

I re-aligned the lens as before, but this time, tucked the nasal capsule under the IOL and then tucked the temporal capsule under the lens for a reverse optic capture (Figure 2).

Her vision improved to J1 at near with a -2.75 + 0.75 x 070 refraction. This (fortunately) very understanding patient was quite satisfied with the final result, and her lens has remained perfectly positioned ever since. In fact, 3 weeks after the second repositioning, we proceeded with toric lens surgery on her right eye, with no further rotational issues.

Looking for reasons

Every degree of malrotation of a toric IOL results in a loss of efficacy of the cylinder correction.¹ In a high-cylinder power lens like this one, a significant rotation can be disastrous. Not only is the cylinder not adequately corrected, but malrotation can actually result in compound imagery that cannot be fully corrected with spectacles.

Looking back at this case, it is difficult to say for certain why the lens rotated. The leading possibility is that the lens was not stable in the bag.

This patient had a relatively long axial length at 25.79 mm and larger white-to-white measurement at 12.72 mm, which point to an unusually large capsular bag. This certainly provides a larger theoretical space for IOL rotation, particularly in the absence of the usual rapid fibrosis. It could be that tapping the sideport incision encouraged lens movement.

However, this was done only once and the lens rotated twice. On the first repositioning, perhaps I was not as aggressive about opening the capsule as I might have been. Timing may have played a factor as well, as a slightly longer wait for the first corrective rotation may have allowed the capsule to contract further.

What I do know is that I’m glad this was a femtosecond laser procedure. This case reinforced that I have no desire to perform toric lens implantation without the laser, for both alignment and centration reasons.

Laser benefits

Re-aligning this toric lens was easier thanks to the intrastromal marks now made with the laser to identify the axis of astigmatism. Those marks were still visible during the repositioning surgeries (Figure 2).

I was also grateful for the precision of the capsulotomy, which was a perfectly round 4.7-mm opening in this case. Although I have confidence in my manual capsulorrhexis surgical skill, the accuracy required for aligning a high-powered toric lens is definitely facilitated by a perfect capsular opening.

Finally, I would not have felt as comfortable attempting the reverse optic capture that I ultimately performed in this eye with a manual capsulorrhexis.

The ability of the femtosecond laser (Catalys, Abbott Medical Optics) to center the capsulotomy on the scanned capsule is a huge benefit in toric or multifocal cases. We know that the pupil dilates asymmetrically and that the pupil center can therefore be different intraoperatively than it was preoperatively.

Furthermore, the pupil center does not always correlate with the center of the capsule where the lens will sit, which can mean that a capsular opening centered on the pupil will not have good overlap of the lens optic for the full 360˚.

In a retrospective analysis, William Wiley, MD, showed that the scanned capsule centration method resulted in more symmetric and complete overlap of the lens optic,²which helps to ensure proper positioning of the lens.

Ray tracing (iTrace Workstation, Hoya Surgical Optics) has also proven to be a valuable surgical tool. In this case, I used it to guide my repositioning.

In another case of blurred vision 1 week after a toric lens implantation, ray tracing showed the lens was well aligned, so the lens was not repositioned. Instead the symptoms were resolved by treating the ocular surface.

Preoperative ray tracing is now obtained on every refractive cataract patient and is considered an essential element in planning an astigmatic correction. I average the ray tracing and Lenstar (Haag-Streit) measurements for the magnitude and axis of astigmatism.

Postoperatively, ray tracing is done only if the result was not optimal and I’m trying to understand why and determine how to fix the problem.

Accurate selection and alignment of toric IOLs is important to obtain optimal outcomes for astigmatic patients. Surgeons are fortunate to have new tools like ray tracing and femtosecond laser that make toric IOL surgery more predictable and increase the chance of superb outcomes.

References

1. Ma JJ, Tseng SS. Effects of steep meridian incision on corneal astigmatism in phacoemulsification cataract surgery. J Cataract Refract Surg. 2012;38:666-671.

2. Wiley WF, Bafna S, Jones J. Optical coherence tomography guided capsule bag-centered femtosecond laser capsulotomy. ASCRS, 2013.

Steven Dewey, MD

P: 719/632-3547

E: deweys@prodigy.net

Dr. Dewey is head of the Colorado Springs Eye Clinic, Colorado Springs. Dr. Dewey is a consultant to Abbott Medical Optics and receives royalties from MST.

Reviewed by Y. Ralph Chu, MD

Bloomington, MN—After noticing a decrease in patients seeking an enhancement after implantation of the accommodating IOL (Crystalens AO, Bausch + Lomb), it occurred to Y. Ralph Chu, MD, that the trend coincided with his shift to performing femtosecond laser-assisted cataract surgery.

Results of a retrospective study comparing cohorts of patients operated on with a conventional manual approach versus using a femtosecond laser (Victus, Bausch + Lomb) confirmed his impression by showing that the LASIK enhancement rate among his accommodating IOL patients fell by almost half, from 11.5% to 5.8%.

Recent: Using femtosecond lasers in eyes with previous surgery

In addition, the femtosecond laser group had better refractive and visual acuity outcomes, said Dr. Chu, founder and medical director, Chu Vision Institute, Bloomington, MN.

“Other surgeons I have talked to seem to be noticing similar trends, but those are anecdotal observations and mine is a first retrospective look at my data,” he said, adding that further study with more rigorous analyses is needed.

Recent: Femto-CKT procedure shows promise for keratoconus stabilization

If the findings can be confirmed, they have clinical importance considering that these premium IOL patients have high expectations for excellent outcomes and a need for LASIK enhancements not only diminishes their satisfaction, but also costs surgeons time and money, he noted.

Courtesy of Y. Ralph Chu, MDComparing enhancement rates

Dr. Chu compared enhancement rates by identifying 130 eyes with the accommodating IOL before and after he switched to the femtosecond laser procedure. Regardless of the technique, he was targeting a 5.5-mm capsulotomy.

At 3 months after surgery, mean MRSE was -0.95 D for the manual surgery cohort and -0.68 D for the eyes that underwent laser cataract surgery. The proportion of eyes in the two groups with an achieved MRSE within 0.5 D of target was 52.4% and 76.8%, respectively, and their mean distance uncorrected visual acuity was 20/40 and 20/30, respectively.

Improved precision (with video)

Improved precision

Dr. Chu said the explanation for why the outcomes in this group of patients improved after he switched to femtosecond-laser assisted cataract surgery cannot be known for sure. He postulated, however, that it is the result of improved precision when using the laser for capsulotomy.

Recent: Strategies for performing a reverse optic capture of toric IOL

“The ability to more consistently create a perfectly circular, perfectly centered, and precisely sized capsulotomy assures anterior capsule rim-IOL overlap, has been shown to reduce IOL decentration and tilt, and may result in greater predictability of effective lens position,” he said.

Because of the accommodating IOL’s flexible platform, its refractive outcomes are probably particularly sensitive to minor variations in capsulotomy accuracy, Dr. Chu noted.

On that basis, he questioned whether such dramatic between-group differences would be observed if similar analyses were conducted for eyes with IOLs having conventional single- or three-piece designs.

Regardless of the type of IOL used, Dr. Chu suggested that a femtosecond laser-based procedure offers other potential benefits.

More: Trends in U.S. refractive surgery, 2015 ISRS survey

“Corneal and astigmatic incisions created with the laser are more consistently precise than those created manually, and so use of the laser may minimize incision leakage and enable more reliable calculations of surgically-induced astigmatism,” he said.

In addition, use of the laser to pretreat the lens reduces ultrasound energy usage along with the need for intraoperative lens manipulation, he said, which lessens stress on the capsule and zonules. These benefits can result in reduced postoperative inflammation and corneal edema.

Y. Ralph Chu, MD

E: yrchu@chuvision.com

Dr. Chu is a consultant to Bausch + Lomb.

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Zephyrhills, FL—A hot topic in cataract surgery is alternative ways to administer perioperative medications with the goal of lowering the incidence of cystoid macular edema (CME). One way to achieve that goal would be the combination of non-steroidal anti-inflammatory drugs (NSAIDs) and transzonular steroids.

“When considering steroids versus non-steroidals versus drops, many of us were trained to use antibiotic steroid and non-steroidal drops before surgery,” Ahad Mahootchi, MD, said. “However, there has been a trend to start using some of these medications in the eye.”

Based on this principle, Dr. Mahootchi had the idea to compare the incidence of CME postoperatively in cases in which steroid or NSAID drops were added to transzonular triamcinolone, moxifloxacin, and vancomycin. “I wanted to see if giving the steroid first, and then the NSAID, made any difference in the incidence of CME.”

More cataract: A complicated case of iatrogenic zonular disinertion

Comparative study

To determine the benefits of this approach, Dr. Mahootchi, in private practice at Zephyrhills, FL, conducted a single-surgeon comparative case series that include 415 patients in each of three groups:

More: How to manage cataracts with ocular surface disease

• Traditional approach of steroidal and NSAID antibiotic drops administered postoperatively and no transzonular medications;

• Transzonular medications with steroid drops (prednisolone acetate) administered postoperatively;

• Transzonular medications with NSAID drops (generic ketorolac) administered postoperatively.

Outcomes

Patients were followed for 90 days, during which period patients with any finding of CME on examination, any visual complaint, and vision below 20/30 were suspected of having CME and underwent optical coherence tomography (OCT).

Dr. Mahootchi reported that in Group 1, the incidence of CME was 1.9%.

“In Group 2, with an incidence of CME of 1.9%, adding the steroid did not increase the incidence of CME, but adding an intravitreal steroid also did not decrease it,” Dr. Mahootchi said. “This confirmed what other investigators have reported previously. Finally, in Group 3, the incidence of CME was 0%, which was unexpected and stunning.”

More Cataract: What is the best way to correct congenital cataracts?

One consideration is that perhaps the Group 3 regimen delays the onset of CME. Therefore, it is unknown what might have happened later than 90 days postoperatively, Dr. Mahootchi noted.

“It was really not valid to compare the results after 90 days with everything that I have done previously,” Dr. Mahootchi explained. “But, we kept counting and concluded that if using a transzonular steroid and an antibiotic at the time of surgery, it is probably beneficial to use an NSAID drop postoperatively to reduce the incidence of CME. However, when we looked at 566 patients who were given only an NSAID in the postoperative period, the incidence of CME increased to only 0.5%. Adding NSAID drops to a transzonular steroid improves CME outcomes overall.”

Ahad Mahootchi, MD

P: 813/779-3338

This article was adapted from Dr. Mahootchi’s presentation at the 2015 meeting of the American Academy of Ophthalmology. He is a speaker for Imprimis Pharmaceuticals.

By Aazim A. Siddiqui MD, Uday Devgan MD, and John G. Ladas MD, PhD, Special to Ophthalmology Times

In the modern landscape of ophthalmology, there is an abundance of intraocular lens (IOL) calculation formulae. This often leads to a clinical dilemma when it comes to choosing the most appropriate formula.Figure 1A: Ladas Super Surface in its raw form

Thus far, there did not exist a perfect formula for all situations, including extremities of keratometry and axial length. Since there was no “one” formula, surgeons resorted to using multiple formulae without a framework to do so.

In developing the “Ladas Super Formula,” the first question we asked was: “How do we capture the best aspects of each formula, while minimizing their drawbacks?”

We looked at these formulae as the algebraic equations that they were. We wondered what we could do by simply graphing these formulae into three dimensions.

James Gleick, the author of Chaos: Making a New Science, said that “graphic images are the key” and “it’s masochism for a mathematician to do without pictures … [Otherwise] how can they see the relationship between that motion and this? How can they develop intuition?”

Once we could visualize these formulae in 3-D, we decided to use this methodology to compare IOL formulae with each other, isolate them and join them together, and what we ended up with was the “Ladas Super Formula” (see Figure 1).

Figure 1B: A somewhat amalgamated Ladas Super SurfaceFigure 1C: Fully coalesced Ladas Super Surface

The Ladas Super Formula is a novel approach of taking the ideal portions of current IOL formulae and stitching them together to create one amalgamated surface and corresponding formula.

(All figures courtesy of Aazim A. Siddiqui, MD)

Real-life examples

Real-life examples

The Ladas Super Formula automatically eliminates the surgeon’s need to mull over the various formulas or adjustments. It relies on peer-reviewed literature to incorporate the needed formulae and adjustments to reach the best-to-date results, and localizes to the correct region on the Ladas Super Surface for every individual patient. Any previously described formula and any future formula can be incorporated into the algorithm.

Figure 2A: The Ladas Super Formula Interface. An example with a short eyeFigure 2B: An example with a standard eye.

Examples of the Ladas Super Formula in action are shown in Figures 2A, 2B, and 2C with a variety of eyes that a surgeon might come across on a daily basis.

Figure 2A shows the formula performing with a relatively short eye. The Ladas Super Formula recognizes that the patient has a short eye, and decides to choose the appropriate formulae and adjustments to yield the most accurate result.

Figure 2B is a similar example but showcases a more generic eye that resembles eyes many surgeons encounter in their operating rooms on a daily basis.

Figure 2C showcases a slightly longer eye. The Ladas Super Formula sees these eyes and decides to incorporate necessary adjustments the formulae need to calculate the most accurate result.

Figure 2C: An example with a somewhat long eyeThe Ladas Super Formula can be accessed free of charge at www.iolcalc.com where it is in beta testing. Surgeons are able to perform lens calculations for their patients and provide postoperative data to further hone the accuracy of the formula.

Comparing formulae

Comparing formulae

With the Ladas-Siddiqui graph, surgeons have the ability to compare multiple formulae to determine where they resemble and differ from each other at entire ranges of corneal power and axial length. By doing so, surgeons can isolate regions of the formulae where a clinical dilemma may occur.

Surgeons, then, can target these areas as those that require the most discussion and improvement. With this graph, surgeons cannot only compare IOL power differences between formulae, but also various input parameters, such as anterior chamber depth (ACD).

Figure 3: The Ladas-Siddiqui graph. A graphical representation that highlights areas where the Ladas Super Formula and the SRK/T formula differ from each other by more than 0.5 D.

Such a task would have taken thousands of eyes to decide upon on a better formula for a given eye. An example of the Ladas-Siddiqui graph is shown in Figure 3, where the Ladas Super Formula is compared with the SRK/T formula.

Evolution of the Ladas Super Formula

Evolution of Ladas Super Formula

The key behind the Ladas Super Formula is its potential to limitlessly improve. The way surgeons go about improving any formula is to optimize it.

Thomas Olsen, the inventor of the Olsen Formula, has emphasized certain points regarding the optimization of a formula. He pointed out that optimization is formula-specific, and that other variables, such as ACD, can be used to “optimize” a formula—as shown in his paper on second eyes.¹

The Ladas Super Formula in its current state represents the best of what already exists. However, to reach the end goal of truly accurate lens calculations, we are in the process of developing an evolutionary mechanism for the Ladas Super Formula so it continues to improve.

We are splitting the Ladas Super Surface into tiny “grid boxes,” which optimizes actual patient data. By making tiny adjustments to all aspects of the Ladas Super Surface in this manner, the current Ladas Super Formula will evolve and improve its accuracy.

We have developed an algorithm that incorporates and analyzes outcome data and adjusts the surface in all aspects. We have recruited multiple major cataract and refractive surgery groups to supply outcome data to aid the optimization process.

Hypothetical user group

We track data from these groups, and use it to adjust and optimize the Ladas Super Surface accordingly. Figures 4A and 4B provide an idea of the progress made by highlighting the number of eyes we already have for optimization purposes within each grid box of the Ladas Super Surface.

This “real-world” data helps the Ladas Super Formula evolve and gives it a dynamic edge, which no previous formula had before, to further refine IOL calculations.

Figure 4A: The Manhattan Graph. A graphical representation of the optimization efforts so far where the Z-axis represents number of eyes that have been collected thanks to the participation of user groups. Figure 4B: A bird's eye view of the Manhattan graph

Hypothetical user group

In Figures 4A and 4B, we have provided a distribution of the data already collected over the given ranges of corneal power and axial range from various user groups. We can see there exists a certain preponderance of eyes in a particular region of the surface.

As we cover every unit of the Ladas Super Surface, we will continue to optimize and perfect the Ladas Super Formula. The more eyes we are able to gather, the more refined the Ladas Super Formula gets. We are crowd-sourcing additional data so we can move up to a 100,000-plus eyes and then, eventually a 1 million or more eyes. Surgeons who wish to participate in this beta testing should contact the authors at the contact information at the end of this article.

Importance of ACD in IOL calculations

Importance of ACD in IOL calculations

With this methodology of 3-D graphical representation, physicians can manipulate these formulae in many different ways. The issue of ACD is an important one when it comes to IOL calculations.

Parameters, such as axial length and corneal power, always have been related to the calculation of ACD calculation. By using these methods, we separate out the ACD from the modern IOL formulae, and figure out the similarities and differences in various ways ACD is calculated in these formulae.

This methodology is further applied not only to simple IOL calculations, but also to post-refractive IOL calculations and to accommodating IOLs.

For post-refractive IOL calculations, we essentially can split the ACD from the vergence calculation of the formulae. We then apply a double K method to treat the ACD and vergence calculation separately. It is generally believed that the ACD calculation is the most critical step in the calculation of IOL power, especially in small eyes with short axial lengths.

Conclusion

Conclusion

The Ladas Super Formula represents a novel step forward in the realm of IOL calculations. By leveraging 3-D mathematical modeling, we are able to understand modern IOL formulae like never before. By doing so, we also are able to take the best pieces of all formulae and amalgamate them together to create a single, ideal surface and consequently derive a formula (i.e., Ladas Super Formula).

The key functionality of the Ladas Super Formula concept lies in its innate dynamism, which leaves room for development of optimization techniques. It is a “living” formula that is constantly evolving, and becomes more accurate as it progresses. By collaborating with a number of user groups and incorporating their actual patient data, we can adjust every grid box of the Ladas Super Surface and further enhance its accuracy.

From this, we can obtain a Ladas Super Formula that will be more accurate than anything before it. The most appealing feature of this concept is that the Super Formula will never cease to improve.

Reference

1) Olsen T. Use of fellow eye data in the calculation of intraocular lens power for the second eye. Ophthalmology. 2011;118:1710-1715. doi: 10.1016/j.ophtha.2011.04.030. Epub 2011 Jul 2.

Aazim A. Siddiqui MD

P: 703/856-0801

E: aazim.siddiqui@gmail.com,

John G. Ladas, MD, PhD

P: 301/928-1448

E:jladas@marylandeye.com

Uday Devgan MD

E: devgan@gmail.com

The authors have an ownership interest in the Ladas Super Formula and Ladas Super Surface and its associated methodologies and processes.

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Take-home message: Femtosecond laser-assisted cataract surgery will continue to lead the transition to a new era in ophthalmology with more precise, customizable, and reproducible capsulotomies.

By George O. Waring IV, MD, FACS, Special to Ophthalmology Times

In the short time surgeons have been performing femtosecond laser-assisted cataract surgery (FLACS), it has become obvious the technology facilitates creation of a precise and accurate capsulotomy.

As settings continue to be refined, surgeons will almost certainly see further improvements in clinical outcomes with femtosecond laser capsulotomy.

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For example, Wendell Scott, MD, has explored the effects of different vertical spacing and incision depth settings on the quality and speed of the laser capsulotomy.¹

Work like this mirrors what surgeons saw in the evolution of femtosecond laser LASIK flaps. Early flaps were not superior to manual flaps but as settings were refined and surgeon experience with the lasers grew, laser flaps quickly outpaced what had been previously possible with manual flaps.

Ophthalmology is heading into a new era where eventually FLACS will gain majority market share compared with manual surgery, just as was observed in corneal refractive surgery. More precise, customizable, and reproducible capsulotomies will be a big part of that transition.

To skip ahead to video, click here.

Size, shape, and strength

Size, shape, and strength

The size of laser capsulotomies has been shown to be more uniform and predictable as well as more circular than manual capsulotomies.² Debate still exists on the overall clinical utility of femtosecond laser-enabled capsulotomies.

Several distinct clinical advantages may result from these attributes. Perhaps the most important benefit may be the increased likelihood of achieving a uniform, 360˚ anterior capsule-optic overlap which should reduce lens tilt and decentration—both of which are particularly important when implanting tilt-intolerant toric or multifocal lenses.

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If there is a less-than-perfect or non-circular manual rhexis that extends to or beyond the optic edge, the potential for anterior optic capture (leading to tilt) increases.

Uniform capsulotomy size and shape could also contribute to more uniform capsular contraction, which may be important in controlling for effective lens position (ELP).

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However, that may not entirely solve the riddle of ELP. For that, it may be necessary to truly modulate the wound-healing process by eradicating lens capsule epithelial cells or by removing the scaffold for LEC proliferation via primary posterior capsulotomy, as described by Dick and Schultz.³Although patient and surgical flow issues still remain, the femtosecond laser has the potential to make primary posterior capsulotomies more routine.

Finally, the consistency of the laser capsulotomy can be beneficial in complex cases. Patients with short eyes, tight anterior chambers, and poor dilation benefit from the predictability of the femtosecond laser.

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In the rare event of posterior capsular compromise, the femtosecond-enabled uniform size and shape capsulotomy lends itself well to optic capture, where consistent apposition of the optic and capsule is essential for successful sulcus placement and maintenance of centration and proper positioning of a three-piece lens.

The same line of reasoning applies in the rare event of negative dysphotopsia or a consistently rotating toric IOL, where a patient may benefit from a reverse optic capture maneuver, in which the optic is maneuvered to rest anterior to the anterior capsule. In such a case, a perfectly circular and sized anterior capsule is more likely to capture the optic in a uniform, planar configuration with less chance of tilt.

There is conflicting evidence on the strength of laser versus manual capsulotomies. Further studies are needed, but I am fairly confident that as laser hardware and settings are optimized—such as increasing the spot and line separation, increasing the laser speed, and with improvement in patient interfaces—the tensile strength of laser capsulotomies should continue to improve from what is already excellent.

Centration

Centration

Proper centration of IOLs—particularly multifocal IOLs—is key to success. Surgeons and the ophthalmic industry are working to improve IOL centration on a number of fronts, ranging from better centration techniques that rely on the subject-fixated coaxially sighted corneal light reflex (SFCSCLR) ⁴ to the use of advanced surgical guidance systems.

Femtosecond laser capsulotomies can be beneficial, as well.

Visit: Cataract Surgery Resource Center

In addition to the benefits of uniform capsular overlap described above, the Catalys laser (Abbott Medical Optics) provides the ability to center the capsular opening on the capsule itself, rather than on the pupil. In my practice, the “scanned capsule” capsulotomy setting has become the default in most cases, except those with very small pupils. It is important to note that in addition to centering on the scanned capsule, multifocal IOLs can be centered on the SFCSCLR intraoperatively (see video).

I prefer a relatively tight range for the capsule diameter. My ideal capsulotomy is 4.9 mm in diameter, which is easier to routinely achieve with a programmable, automated laser capsulotomy. My minimum femtosecond enabled diameter in eyes with poor dilation is 4.7 mm, and I will sometimes go as high as 5.1 mm, particularly in mature cataracts.

In eyes with poor dilation due to use of tamsulosin or other medications, it can be challenging to get the desired size capsulotomy with capsule-centered because of the system’s safety zones that prevent encroaching on the iris margin. In such eyes, my default setting is maximized and centered on the pupil.

In cases where sufficient diameter is still not realized, I use a manual override technique to optimize the diameter, in which the captured iris boarder is enlarged to larger than what is captured, which allows the rhexis to expand out to the iris margin when necessary.

The goal is always a uniform shape that produces a uniform overlap. Being able to manipulate the laser’s diameter and centration settings helps to avoid decentration in these challenging eyes.

Future developments

Future developments

Femtosecond laser capsulotomies may also make entirely new approaches a reality in the future. For example, better understanding the biometric data that laser systems are gathering from OCT scans of the capsule can provide new insights into anterior-posterior ELP, the cause of refractive surprises, and how best to use this data for improved outcomes.

Already, much has been learned about the variation of crystalline lens anatomy. Not only is there wide inter-patient and inter-eye variation in capsule dimensions, but there is also the finding that capsule dimensions relative to axial length may be important. It is possible that in the future, IOL companies may begin to focus more on the potential for sizing lenses to the capsule in order to improve ELP. The concept of a primary posterior capsulotomy to reduce capsular contraction and possibly primary optic capture techniques is also exciting. Much of this is due to the fact that this is now imaged-guided surgery.

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Capsulotomy-fixated IOL designs have also been proposed by a number of surgeons, including Julian Stevens, MD; Burkhard Dick, MD; Sam Masket, MD; and Roberto Zaldivar, MD. The aforementioned femtosecond laser capsulotomy benefits are desirable and possibly necessary for these IOL innovations.

Femtosecond-enabled laser capsulotomy is one of many benefits of FLACS. With the precision of laser-enabled limbal-relaxing incisions, the customizable lens fragmentation patterns and softening, and image-guided surgery, FLACS is an important innovation in anterior segment surgery.

Video

Centering a multifocal IOL on the subject-fixated coaxially sighted corneal light reflex (Video courtesy of George O. Waring IV, MD, FACS)

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References

1. Scott W, Tauber S, Gessler JA, et al. Clinical comparison of effect of sub-one second femtosecond laser capsulotomy on capsulotomy irregularities. Paper presentation, ASCRS 2015.

2. Friedman NJ, Palanker DV, Schuele G, et al. Femtosecond laser capsulotomy. J Cataract Refract Surg. 2011;37:1189-1198.

3. Dick H, Schultz T. Primary posterior laser-assisted capsulotomy. J Refract Surg. 2014;30:128-133.

4. Chang DH, Waring GO IV. The subject-fixated coaxially sighted corneal light reflex: A clinical marker for centration of refractive treatments and devices. Am J Ophthalmol. 2014;158:863-874.

George O. Waring IV, MD, FACS

P: 843/216-2020

E: georgewaring@me.com

Dr. Waring is associate professor of ophthalmology and director of refractive surgery, Storm Eye Institute, Medical University of South Carolina (MUSC), Charleston, and serves as medical director at MUSC’s Magill Vision Center. Dr. Waring also serves as adjunct assistant professor of bioengineering, College of Engineering and Science, Clemson University, Clemson, SC.

Take-home message: A sustained-release dexamethasone intracanalicular depot may be able to treat post-cataract surgery inflammation without causing spikes in IOP. The product’s one-time administration may also improve compliance and convenience.

By John Berdahl, MD, Special to Ophthalmology Times

Sioux Falls, SD—With all the improvements in cataract surgery over the years, the need for better topical therapies post-procedure continues to be unmet.

Post-surgical anti-inflammatories—such as corticosteroids—are a vital element in the process to promote healing and combat pain and inflammation, which can lead to other issues. However, while necessary to obtain positive outcomes, the inconsistency of patient delivered steroids drops could lead to variable response.

Additionally, the post-surgical drop regimen can be inconvenient, costly, and confusing for patients. Many struggle with adherence, especially those previously inexperienced with drop administration.¹

These issues are exacerbated when long-term administration is necessary. According to IMS Health Data, more than 20 million anti-inflammatory eye drop prescriptions were filled in 2015—corticosteroids comprising about 8.9 million of those.²Studies of patients with chronic diseases have found that only 10% of patients showed a consistently proficient pattern of compliance through 1 year³ and only 15% adhered consistently over 4 years.⁴

Though these studies highlight long-term medications, they serve to show the difficulty patients often have with self-administering ocular medications. Treatment options that reduce the number of drops a patient must administer and put control over adherence in the physician’s hands are of great benefit to the patient. With the physician at the helm, medication delivery is assured—helping improve positive outcomes.

New mechanism of action

The question then becomes: What is the best way to deliver necessary steroid medications? Dropless cataract surgery (Imprimis Pharmaceuticals) may be a viable approach.

However, some physicians believe a postoperative nonsteroid anti-inflammatory drug is still necessary to combat inflammation. Additionally, not all patients are good candidates for the dropless approach due to preference or pathology. Those who will need a steroid post surgery will continue to struggle through the confusing drop regimen and often expensive topical therapy treatments.

With the advent of an ocular pain treatment (Dextenza, Ocular Therapeutix), ophthalmologists worldwide may have a new alternative to traditional steroid therapy with drops. The preservative-free, hydrogel-based, intracanalicular depot delivers a sustained-release dose of dexamethasone over a period of 4 weeks.

The intracanalicular depot form-fits within the canaliculus. The depot becomes soft following insertion through contact with moisture, thereby contracting in length and expanding in diameter once in place. As it is administered by the physician in a one-time procedure, adherence is assured and convenience for the patient is greatly improved.

Retention rates in the phase II trials were strong, with the intracanalicular drug depot group demonstrating 100% retention through day 14, and 97% through day 30.⁵ Current phase III trials are demonstrating similarly strong rates.

Placement of the intracanalicular depot is a simple procedure that is familiar to ophthalmologists and well tolerated by patients.

However, the depot will swell after contact with moisture so surgeons must be deliberate when inserting it. The depot also contains a visualization aid for retention monitoring, making the depot visible under blue light and under blue light with a yellow filter, though it will not be visible under normal light. Once drug delivery is complete, the depot is essentially hydrolyzed and exits the patient’s nasolacrimal system without the need for physician intervention or removal.

Dexamethasone is one of the most potent corticosteroids available. Widely used in ophthalmology decades ago, it fell out of favor due to a reputation for IOP spikes. However, in small, controlled aliquots IOP spikes may not be a concern as in decades past.

An intracanalicular drug depot essentially provides an improved delivery system for a familiar drug while addressing the former drawbacks. The potency of the drug allows for the small size of the delivery system, as less of the drug is needed for the desired effect.

While an argument may be made that a less potent steroid would be a better alternative as it may involve lesser risk of IOP spikes, a less potent steroid would not solve the problem of delivery as a greater quantity would be required. With intracanalicular drug depots, it is possible to provide significant positive results with a small volume.

Safety and efficacy

The intracanalicular depot is currently in phase III trials for the treatment of postoperative inflammation and pain and is illustrating promising safety and efficacy. While this data continues to be analyzed, the drug appears to be well tolerated with a good safety profile as evidenced by the fact that in the clinical trials, despite using a very potent steroid, a comparatively low rate of IOP spikes (≥10 mm Hg) were demonstrated posterative day 14 (1/322 or 0.3%).

In the phase II data,⁵ the intracanalicular depot group demonstrated statistically significant superiority over placebo for the absence of pain and cells in the anterior chamber, evidence that the delivery system of this well known drug is helping mitigate the known unwanted side effects of its potency.

Looking forward

It remains to be seen how intracanalicular drug depots will change treatment regimens if FDA approval is gained. Physicians strive to do what is in patients’ best interests and that includes providing the safest, most cost-effective, convenient, and efficacious options for postoperative care.

Use of intracanalicular drug depots over an approach, such as dropless cataract surgery, would necessitate the addition of an antibiotic drop post-surgery. However, one point in the intracanalicular depot’s drug favor is it will be an FDA-approved medication and delivery system. This will be of significant importance in terms of insurance reimbursement pathways.

Cataract surgery is already an impressive procedure. Being able to reduce the inconvenience and confusion of a strict topical therapy regimen post-surgery for patients while simultaneously providing optimal prevention of inflammation is an exciting development.

References

1. An JA, Kasner O, Samek DA, Lévesque V. Evaluation of eyedrop administration by inexperienced patients after cataract surgery. J Cataract Refract Surg. 2014;40:1857–1861.

2. IMS Health.

3. Friedman DS, Quigley HA, Gelb L, Tan J, Margolis J, Shah SN, Kim EE, Zimmerman T, Hahn SR. Using pharmacy claims data to study adherence to glaucoma medications: methodology and findings of the glaucoma adherence and persistency study (GAPS). Invest Ophthalmol Vis Sci. 2007;48:5052-5057.

4. Newman-Casey PA, Blachley T, Lee PP, Heisler M, Farris KB, and Stein JD. Patterns of glaucoma medication adherence over four years of follow-up. Ophthal. 2015;122: 2010–2021.

5. Ocular Therapeutix. Dextenza (sustained release dexamethasone) intracanalicular depot. Retrieved from Ocular Therapeutix website Feb. 28, 2016. http://www.ocutx.com/pipeline/dexamethasone-punctum-plug.

John Berdahl, MD

E: john.berdahl@vancethompsonvision.com

Dr. Berdahl is in practice at Vance Thompson Vision, Sioux Falls, SD. He is a paid consultant for Ocular Therapeutix.

Take-home message: A new instrument can be used during cataract surgery to remove silicone oil placed in the vitreous cavity during prior surgery for complicated retinal detachment.

By Nancy Groves; Reviewed by Lawrence R. Goldberg, MD

Saint Petersburg, FL—Using a new instrument (Goldberg Silicone Oil Extractor, Rhein Medical), cataract surgeons can perform a one-stage procedure for cataract extraction, IOL implantation, and silicone oil removal.

This is contrasted with a two-stage procedure of first having the retinal surgeon extract the silicone oil, and at a future date, having the cataract surgeon remove the cataract and implant the IOL.

The two-stage procedure is less desirable since it requires two separate operating room sessions, is more costly, and lengthens the visual rehabilitation of the patient, said Lawrence R. Goldberg, MD, an ophthalmologist in private practice in Saint Petersburg, FL, who designed the tool in collaboration with Rhein Medical.

The instrument is a reusable cannula designed to both stent open the temporal cataract wound to allow egress of the silicone oil out of the eye and aspirate any residual oil that remains in the vitreous cavity. Dr. Goldberg said.

A significant oil bubble remains in about 1/3 of cases, resistant to removal by irrigation through the sideport incision, ultimately requiring controlled aspiration utilizing the new cannula.

In the one-stage surgical procedure, after cataract removal and posterior capsulorhexis, a 23-gauge anterior chamber maintainer is inserted through the sideport incision, and in the majority of cases the oil is removed after it floats on top of the balanced salt solution (BSS) and out the stented temporal wound.

In some patients, a substantial oil bubble remains in the posterior chamber that will not float through the posterior capsulorhexis and out the main incision regardless of the patient's head position. These are the cases for which the new cannula is especially beneficial.

To extract resistant oil bubbles, the cannula is inserted down through the posterior capsulorhexis, near or just peripheral to the viewed edge of the pupil (depending on the bubble's position). Then the downward facing port is slightly embedded into the oil bubble's surface, occluding its opening.

Next, the anterior chamber maintainer's tubing is kinked to stop irrigation into the eye; sideport irrigation will push the oil bubble into the periphery, out of view.

Lastly, full aspiration is engaged, which will slowly diminish and totally remove the remaining oil bubble. Complete removal of the oil may take 15 to 20 minutes. Viscoelastic is then placed in the capsular bag, followed by posterior chamber IOL implantation.

“It is noteworthy to mention that stopping irrigation into the eye by kinking the tubing of the chamber maintainer will not cause collapse of the anterior chamber as long as the port of the cannula is in continuous contact with the oil bubble, since the aspirated oil occludes the lumen, sealing it, so that only oil is removed, leaving the balanced salt solution in the eye,” Dr. Goldberg said.

He added that it is advisable to “prime” the cannula and tubing with oil when initially using the cannula to stent the wound open by placing the port into the main body of oil through the posterior capsulorhexis and aspirating until it is all removed from the eye or a residual oil bubble is noted.

During the procedure, any time oil is being aspirated it is normal to hear the machine's warning sound signifying a clogged line.

“This just means the oil is moving very slowly; the warning should be ignored and full aspiration mode should be continued,” Dr. Goldberg said.

Impetus for design creation

He began thinking about designing an instrument for removing silicone oil several years ago, having experienced difficulty in a case where a residual oil bubble could not be fully removed despite moving the patient's head into a dependent position.

At that time, the only available aids discussed in the literature or demonstrated in videos were using a short, sharp 19-gauge needle to stent the wound open or placing an irrigating anterior chamber maintainer through the sideport incision.

During one of Dr. Goldberg’s cases involving an oil bubble resistant to removal, he found an old angled irrigating instrument with a port opening that was angled down and connected it to the aspiration tubing. Although it sucked out the oil bubble, the instrument had a small lumen, causing the oil removal to be very slow.

He concluded that a similar instrument with a larger lumen might be more effective at extracting oil. He and the team at Rhein Medical then developed such an instrument, which was launched last fall.

In many cases where silicone oil has been placed in the vitreous cavity to repair a complicated retinal detachment, tiny bubbles of emulsified oil travel around the zonules and end up in dependent positions of the anterior chamber. They can be observed layered at the top of the anterior chamber when the patient is examined at the slit lamp.

During cataract surgery on a supine patient, the oil is layered up against the central corneal endothelium, blocking the view of anterior chamber details, so its removal is required. Initially, anterior chamber oil removal is accomplished by making a sideport incision and irrigating out as much oil as possible using a regular 27-gauge angled cannula connected to a syringe with BSS.

If any oil bubbles remain, they can be cleared from the anterior chamber by injecting viscoelastic through the sideport incision prior to performing the anterior capsulorhexis.

During the cataract surgery portion of the procedure (routine phacoemulsification), Dr. Goldberg recommends a 3-3.5 mm temporal clear corneal incision depending on the size of the IOL planned (6 or 6.5 mm), which will allow the oil to more readily flow out around the silicone oil extractor cannula as it stents the wound open.

Dr. Goldberg routinely makes a 5-mm anterior capsulorhexis opening.

“I strongly recommend that during posterior capsulorhexis, the anterior chamber should not be overfilled with viscoelastic, and the capsular bag should not be inflated at all, leaving the anterior and posterior capsule leaflets in contact,” Dr. Goldberg said.

When initiating the posterior capsular tear, oil that bulges forward will be held back by the viscoelastic. He prefers making a 3.5-4 mm posterior capsulorhexis opening so he can implant his regular 6-mm, one-piece posterior chamber IOL in the bag. If the posterior capsulorhexis is larger than 4 mm, then a three-piece 6.5 mm posterior chamber IOL is preferred.

Lawrence R. Goldberg, MD

E: rhinoeye@yahoo.com

Dr. Goldberg developed the Silicone Oil Extractor in coordination with Rhein Medical.

By Richard Packard, MD, FRCS, FRCOphth, Special to Ophthalmology Times

London—Microincision cataract surgery (MICS) has become a standard procedure for cataract removal. The widely practiced biaxial and coaxial procedures allow for minimally invasive, sutureless surgery with fast wound healing and almost instant visual recovery.^1,2

However, because microincisions provide a limited amount of room to insert and maneuver a phaco tip during lens removal, there has been an increasing demand for narrower phaco tips. These should allow for easier manipulation within the phaco wound, even with incisions of 1.8 mm.

MICS & MIGS: Combined surgery with microstent devices

In response to this demand, I developed a phaco tip (Packard 0.7 Phaco Tip, MicroSurgical Technology), that was intended particularly for coaxial MICS (CMICS). The instrument is part of a family tips with an outer diameter of 700 μm. These tips offer a narrower design than those generally used for MICS, which usually have an outer diameter of between 800 μm and 1 mm.

The Packard family of phaco tips is available in a wide assortment, bent at either 12° or 20° and offered in Dewey Radius, traditional, and reverse bevel versions. Although these phaco tips were designed initially for CMICS and bimanual MICS (BMICS), they also work very effectively with appropriate sleeves for incisions of up to 2.8 mm.

One of the most significant advantages of a narrow phaco tip is that it offers improved visibility of intraocular structures during surgery when compared with larger phaco tips.

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Particularly important with microincisions, a 700-μm phaco tip provides more room within the tunnel incision/sleeve for the surgeon to maneuver freely but also less restriction of irrigation fluid entering the eye.

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This should assist in maintaining the anterior chamber when high vacuum and aspiration flow rates are in use. The curved tip reduces the overall need to tilt it downward during surgery, which gives a more comfortable hand position—especially when operating temporally. This results in a reduced amount of wound stress and unintentional enlargement of the incision.

No reduced performance

Despite the narrow outer diameter of the tip, due to its thin wall the internal diameter of the Packard phaco tips is 570 μm, which is comparable to other MICS phaco tips that have a wider outer diameter. This means that with appropriate fluidics settings, the 700-μm phaco tip is not hindered by reduced performance during phacoemulsification. Also, the narrow profile and thin wall cuts through denser cataracts more effectively than tips with a larger profile.

In addition to offering efficiency through a narrow and angulated design, it is also important that a phaco tip is widely compatible with the various standard phacoemulsification platforms. The phaco tips fit to certain platforms (Alcon’s Infiniti and Centurion platforms using torsional phaco), but also work well with other systems (Stellaris, Bausch + Lomb; Whitestate Signature, Abbott Medical Optics), although a slightly shorter version will need to be ordered.

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Although using a curved phaco tip is mandatory for effective torsional phaco, as on the Infiniti and Centurion, I have found that a tip of this design enhances the behaviour of Ellips FX on the Signature over a straight needle.

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The narrower profile and ergonomics of a 700-μm phaco tip mean that there are slight differences in the way that the tip is handled, compared with wider-diameter tips. In my experience, however, I have found that this does not entail a significant learning curve. In our practice, most trainees start off with a divide-and-conquer nucleofractis technique. The 700-μm phaco tip allows for the easy creation of a very precise trench. The narrow profile of the tip means that it and the sideport instrument can then be placed right down in the bottom of the trench, making it easier to crack the nucleus.

Surgical pearls, experience

Surgical pearls, experience

For medium cataracts, I use a “soft chop” technique. After creating a small opening in the nucleus, the tip can then be buried deeply within it. I would recommend performing such a technique with a low vacuum setting of about 70-75 mm Hg and proceeding with a vertical chop. If the vacuum is too high, the piece of nucleus that is embedded in the phaco tip tends to get pulled through and there is little further purchase of nucleus tissue.

For a denser cataract, you may find that the nucleus rotates after the tip is buried and you begin the chopping procedure. In this case, it useful to pull with the hand wielding the chopper and simultaneously pushing with the hand holding the phaco tip to produce the hard chop of the nucleus. I normally use a vacuum of 400 mm Hg.

With most cataracts when using torsional phaco, burst mode is recommended. When faced with an extremely dense cataract, I would add 50% pulsed longitudinal phaco on top, for optimal efficiency. Although this means temporarily using higher power levels, less cumulative power is used overall because the narrow and angulated tip works more efficiently than a wider one. In a case study in 2009, the phaco tip (at 700 μm) offered the least cumulative dissipated energy, compared with four other tips during CMICS for dense cataracts.

Today, femtosecond lasers offer an effective tool to chop the nucleus safely in dense cataracts. However, even if the nucleus of a dense cataract is pre-chopped with a laser, there is often still the need to use a significant amount of phaco power afterward to remove the fragments from the eye. Using a 700-μm phaco tip to chop the nucleus into eight pieces in a similar manner to the laser uses a similar amount of energy for removal of the nucleus.

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As described above, this narrow-profile, angulated phaco tip provides surgeons with a means for safe and effective surgery, whether performing CMICS, BMICS, or surgery utilizing incisions that range from 1.8 to 2.8 mm.

By offering more room for maneuvering, there should be less wound stress. Despite the narrow tip, with appropriate fluidics and ultrasound settings there should be no loss of functionality. It is particularly useful to have a tip that can be used with a wide range of different machines, techniques, skills, and clinical settings.

Check out: Why pediatric ophthalmologists don't go to late night parties

References

1. Alió JL, Rodriguez-Prats JL, Galal A. Micro-incision cataract surgery. Highlights of Ophthalmology International, Miami, USA (2004).

2. Elkady B, Piñero D, Alió JL. Corneal incision quality: microincision cataract surgery versus microcoaxial phacoemulsification. J Cataract Refract Surg. 2009;35:466–474.

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Take-home message: Kevin M. Barber, MD, explains how a dropless cataract surgery approach helps to alleviates anxiety, cost burdens, and adherence issues associated with traditional drop therapy.

By Kevin M. Barber, MD, Special to Ophthalmology Times

Deland, FL—When a certain practice pattern has persisted over decades, it can be difficult to convince physicians to change.

However, this desire to cling to traditional techniques has more to do with habit than a basis in scientific data and literature. This struggle is currently occurring with medication following cataract surgery.

Traditionally, patients must endure weeks of a strict multi-drop regimen pre- and postoperatively. This confusing and often costly requirement typically results in dissatisfied patients, office staff, and physicians alike. Continually rising costs can at times reach up to $650 per eye,¹ an amount few patients can manage. Even those who can obtain the correct drops often struggle with compliance.^2,3

The drops are administered to prevent infection and inflammation, most notably endophthalmitis.

However, there is no solid scientific evidence that these drops actually aid in prevention. Conversely, studies have shown that while there is a statistically insignificant drop in the rate of endophthalmitis using topical therapies, occurrences of this condition are five times less likely to occur when medications are injected intracamerally.^4,5

Injecting medications has also been shown to decrease the development of antibiotic resistance, which is a common occurrence in topical antibiotic applications.^6-8

If injecting these medications intracamerally produces such exceptional results, it stands to reason that injecting intravitreally will work even better. Studies have shown intravitreal injections of triamcinolone acetonide and moxifloxacin hydrochloride (Tri-Moxi, Imprimis Pharmaceuticals) and triamcinolone-moxifloxacin-vancomycin (Tri-Moxi-Vanc, Imprimis) not only reduce rates of infection and inflammation, and nearly eliminate endophthalmitis, but significantly reduce occurrences of cystoid macular edema (CME) as well.^9,10

Yet, the ophthalmic surgical community as a whole continues to cling to traditional methods, despite science pointing to a superior technique. It is time for a paradigm shift.

Addressing surgeons’ concerns

In addition to combating decades’ worth of training and experience with topical therapies, many surgeons may hesitate due to the compounded nature of these injections.

However, the reality is compounded medications—such as an epinephrine and lidocaine concoction—are used on a regular basis in ocular surgery. Concerns with these new compounds may also stem from the slightly higher risk of injecting into the vitreous, though published studies show the benefits far outweigh any risks.^9,10

Other concerns may be related to a policy modified in January 2015 where CMS took the position that dropless therapy is both “covered” and paid for, since it is part of the surgery and the surgery is covered and paid for through the facility fee. Surgeons need for CMS to understand that the actual cataract surgery is unchanged by dropless therapy, which is simply an alternative means of administering post-surgical drops which are covered under Medicare Part D. Through a Cataract Surgeons for Improved Eyecare (CSIE) (improvedeyecare.org) co-sponsored study data supports that dropless therapy could save CMS over $7 billion in a ten-year period while saving patients $1.4 billion in out-of-pocket copayment costs.¹¹

In the meantime, the use and popularity of dropless therapy continues to rise and more and more patients are demanding this procedure. Today the small cost of dropless therapy is offset by the cost saved in increased patient recommendations and staff productivity. Word of mouth is spreading and patients are seeking out surgeons who utilize the dropless approach.

Additionally, many physicians may not realize the amount of time their staff spends on drop issues.

In my own practice, it was necessary to employ a full-time triage technician who spent 75% of the time just on drop concerns from patients, insurance providers, and pharmacies. With the implementation of the intravitreal injection into my surgical procedure, this technician can now focus on more productive endeavors.

Surgical pearls

I perform 95% of my injections transzonularly. This is my preferred approach as I am already in the eye and do not need to create another injection site. The important issue here is to carefully manipulate the cannula in order to get it posterior enough that the medication stays in the vitreous and does not reflux back into the anterior chamber. However, the ciliary body must be avoided or it is possible to cause a hemorrhage or hyphema.

I will utilize a pars plana approach for my high hyperopic patients with a short axial length, typically less than 22 mm, as they are at higher risk for iris prolapse due to smaller vitreous volume. In these cases, I go in through the pars plana and “burp” the wound to bring the pressure down. This technique has been well tolerated by patients.

One of the most important steps is educating not only patients, but also staff members as to what to expect post procedure. Patients may experience floaters for up to a few days post surgery as the medication slowly dissipates. Staff members have been traditionally trained to be aware of floaters as they may indicate the risk of a retinal tear or detachment. As long as staff members and patients are aware that floaters after a dropless procedure are normal, concerns are generally minimal.

In my own practice, an educational sheet for patients explains the difference between floaters caused by injected medication and those that may indicate retinal problems. Those caused by medication are generally superior and blob-like in shape and should continue to dissipate as time goes on. Floaters caused by injected medication are not typically associated with flashes of light.

Experience with dropless therapy

Dropless therapy has been intriguing from my first exposure a decade ago while in Ethiopia, where intracameral or intraocular injections are utilized to combat the cost and availability barriers to the patients there. The results were impressive. When I discovered the intravitreal method of injecting triamcinolone-moxifloxacin-vancomycin about 18 months ago, I quickly went from offering it as an option to making it a standard of care for nearly all patients.

The small percentage of patients who do not receive this therapy are typically advanced-stage glaucoma patients who are already on maximum medical therapy and have significant nerve damage, and who could not tolerate a steroid response if one occurred. Though these responses are few and far between, I prefer to err on the side of caution where these patients are concerned. For monocular patients, I provide the facts of the slight vision lag they may experience due to floaters post-procedure and give them the choice on whether to receive the injection or traditional drops. Nearly all have elected for the dropless approach.

Bottom line: though there may be a few minor drawbacks, these do not outweigh the basic reality that this is the best therapy for the patient. The approach alleviates anxiety, cost burden, and adherence associated with traditional drop therapy, and has been scientifically documented to provide improved infection and inflammation prevention than previous methods.

Kevin M. Barber, MD

E: kevinbmd@yahoo.com

Dr. Barber is a board-certified ophthalmologist, Central Florida Eye Specialists and Laser Center, Deland, FL. He did not indicate any proprietary interest in the subject matter.

References

1. Andrew Chang and Co., LLC. “Analysis of the Economic Impacts of Dropless Cataract Therapy on Medicare, Medicaid, State Governments, and Patient Costs.” October 2015.

2. Stone JL, Robin AL, Novack GD, Covert DW, Cagle GD. An Objective Evaluation of Eyedrop Instillation in Patients With Glaucoma. Arch Ophthalmol. 2009;127:732-736.

3. Schwartz GF, Hollander DA, Williams JM. Evaluation of eye drop administration technique in patients with glaucoma or ocular hypertension. Curr Med Res Opin. 2013;29:1515-1522.

4. Barry P, et al. ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study. J Cataract Refract Surg. 2006;32:407-410.

5. Shorstein NH, Winthrop KL, Harrinton LJ. Decreased postoperative endophthalmitis rate after institution of intracameral antibiotics in a Northern California eye department. J Cataract Refract Surg. 2013;39:8-14.

6. Kim SJ, Toma HS. Antimicrobial resistance and ophthalmic antibiotics: 1-year results of a longitudinal controlled study of patients undergoing intravitreal injections. Arch Ophthalmol. 2011;129:1180-1188.

7. Hwang DG. Fluoroquinolone resistance in ophthalmology and the potential role for newer ophthalmic fluoroquinolones. Surv Ophthalmol. 2004; 49 Suppl 2:S79-S83.

8. Gaynor BD, Chidambaram JD, Cevallos V. et al. Topical ocular antibiotics induce bacterial resistance at extraocular sites. Br J Ophthalmol. 2005;89:1097–1099.

9. Liegner J. Better surgery through chemicals. Presented at the American Society for Cataract and Refractive Surgery Annual Meeting. April 25-29, 2014. Boston.

10. Galloway MS. Intravitreal placement of antibiotic/steroid as a substitute for post-operative drops following cataract surgery. Presented at the American Society for Cataract and Refractive Surgery Annual Meeting. April 25-29, 2014. Boston.

11. Andrew Chang and Co., LLC. “Analysis of the Economic Impacts of Dropless Cataract Therapy on Medicare, Medicaid, State Governments, and Patient Costs.” October 2015.

Take-home: Cataract surgery assisted by viscosplit and crack gives good results compared with standard phacoemulsification.

Introduction

Introducing femtolasers into cataract surgical procedures has advantages, but also disadvantages such as a range of additional complications.¹ This raises the question of whether this expensive technology adds sufficient benefit to previous techniques. Therefore, scientific comparison of different surgical methods with respect to safety, benefits for the patients and cost is necessary. The aim of this paper, which is based on a presentation at the ESCRS 2010 meeting,² is to compare different phaco techniques in order to evaluate their advantages and disadvantages and to derive implications for future directions in cataract surgical methodology.

In order to investigate and disentangle the costs and benefits of different cataract surgical methods, this study compared cataract surgery assisted by viscosplit and crack (VSC) with that performed using standard phacoemulsification. These are well-known variations of mechanical fragmentation of the nucleus phacofracture divide-and-conquer and bimanual chop techniques,^3–5 all performed at our eye surgery centre in Augsburg, Germany.

Patients and methods

Patients and methods

The study included 200 patients aged between 50 and 75 years. Inclusion criteria related to the hardness of the lens nucleus only.^4,5. Patients with previous eye surgery, retinal disorders, glaucoma, cataract lenses that were softer or harder as well as rock-hard lens nuclei were excluded.

All patients had a comprehensive baseline preoperative assessment. Biometry was performed 8–4 weeks prior to surgery. All surgery was performed by the author.

Our collected data included all biometric measurements as well as pre- and postoperative endothelial cell counts.

During surgery, the following data were collected:

1. Quantity of balanced salt solution (BSS, mL) consumed during phacoemulsification and overall.

2. Ultrasound energy; ultrasound time.

Best corrected visual acuity (BCVA) data were obtained on the first day, as well as 4 weeks and 3 months after surgery; endothelial cell counts were taken 6 weeks postoperatively. These data were compared retrospectively with data from our database of previous conventional one-handed and bimanual phacofracture procedures. Statistical analyses were performed using the sampled t-test. Differences were accepted as significant when the p value was less than 0.05.

Surgical Technique

Surgical technique

After peribulbar anaesthesia, surgery was begun with postlimbal incisions, which were neutral to astigmatism. The main incision size was <2.2 mm, using a temporal limbal approach with two side-port incisions. The continuous curvilinear capsulorhexis (CCC) diameter was 5.5–5.8 mm. After CCC, hydrodissection was performed with a 27 gauge cannula; hydrodelineation was achieved using a sharp, slightly bent cannula to perform a smooth infusion of BSS within the sometimes rigid lens material.

FIGURE 1

(FIGURE 1) The hydrodissection cannula (Klaas/Geuder).

After protection of the endothelium with Viscoat® (Alcon, Fort Worth, USA), viscoelastics were injected at the edge of the most visible golden ring between cortex, epinucleus and lens nucleus. Repeated delineation with viscoelastics was performed (‘viscodelineation’).

Injection behind the lens nucleus from the surgeon’s point of view allowed one pole of the nucleus to shift forward. We also installed a retronuclear pad of viscoelastics to the posterior pole of the core, which made it more easy to lift without zonular affection and created a protection shield for the posterior capsule.

FIGURE 2(FIGURE 2) Split bevel up and split bevel down (Klaas/Catena Inc).

With two specifically designed lens-splitting instruments (Klaas/Catena USA Inc), the lens nucleus can be cut into small pieces: as many as you like. The cross-sections of these instruments are triangular and they have a rounded tip (to protect the lens capsule) and one sharp edge on top (bevel-up and bevel-down) in order to cut the nucleus easily.

FIGURE 3AFIGURE 3CFFIGURE 3DIGURE 3B

(FIGURE 3A–D) Viscosplit technique: segmentation of the lens nucleus.

The surgical cataract procedure was performed using the Ocusystem II Advantage Art-System (Surgical Design Corporation, NY, USA). Maximal ultrasound power was 30%, initial flow 12 mL/min, maximum flow 25 mL/min, vacuum settings min: –120 to max: –350.

Phaco-emulsification of the lens fragments was carried out using specially designed phaco tips. The particular advantage of this new generation of phaco tips lies in its edgeless and non-sharp design. The aperture of the tip is situated more on the side of the ultrasound tip, which makes the procedure safer with regard to protecting the lens capsule. In addition, the side-orientated opening provides greater suction of the lens material. Therefore, it is no longer necessary to cut the lens material.FIGURE 7

(FIGURE 7) Shark™ phaco tips.

Epinucleus and cortex removal was done with the same phaco needle followed by irrigation/aspiration with a bimanual technique (Geuder, Heidelberg, Germany).

Analyses and results

Analyses

We compared results concerning different parameters obtained by the viscosplit technique (n=200) with results obtained with the standard phaco technique, bimanual (n=83) and one-handed (n=50). Values were compared using two-sample t-tests.

Results

In the viscosplit group (see Table 1) mean BSS volume during phaco was only 12.0 mL; the other two groups needed 35 mL (one-handed) and 65 mL (bimanual).

Both ultrasound time and energy were reduced by between 60% and 80% with viscosplit compared with conventional phaco-emulsification techniques.

All patients had a BCVA of 20/25 or better, and reading speed showed considerable amelioration. BCVA was significantly better in the viscosplit group the day after surgery. At 6 weeks, BCVA showed no difference between the groups.

There was very little endothelial cell loss 6 weeks postoperatively, and no significant difference between viscosplit and the two conventional surgery groups.

Table: Viscosplit versus standard phaco

TABLE 1: Viscosplit versus standard phaco. All values are mean (standard deviation) unless otherwise stated.

	Viscosplit group Shark tip (n=200)	Standard phaco group; bimanual phacofracture Mini cobra tip (n=83)	Standard phaco group; one-handed phacofracture Mini cobra tip (n=50)
	Pulse mode 30 Hz Incision size 1.9–2.0 mm	Pulse mode 30 Hz Incision size 2.0–2.2 mm	Pulse mode 30 Hz Incision size 1.9–2.0 mm
Total BSS volume, mL	25.0 (5.0)	80.5 (11)	62.0 (10)
Phaco-only BSS volume, mL	12.0 (3.0)	65.0 (6.0)	35.0 (4.0)
Ultrasound time, s	14.3 (2.1)	44.3 (3.1)	31.3 (3.5)
Ultrasound energy, mJ	3.1 (0.2)	8.0 (0.2)	4.0 (0.3)
BCVA, day 1	1.0	0.63 (0.1)	0.7 (0.1)
BCVA, week 6	1.0 (0.05)	1.0 (0.05)	1.0 (0.1)
Endothelial cell loss, %	<0.1	<1.5	<1.0

Discussion and summary

Discussion and summary

We have demonstrated excellent results for this innovative procedure in 200 patients, which were compared with the results of two control groups that were treated using conventional procedures.

Our findings suggest the minicoaxial phaco-emulsification technique using the VSC procedure to be an energy- and time-saving method. Owing, presumably, to better flow dynamics and to not grooving the nucleus, this method has advantages over all bimanual methods. Comparing the results from this series of patients with those from former patients whose surgery used bimanual chopping methods by the same surgeon, we noticed faster recovery and better initial results.

We can show that the technique described here has considerable advantages. First, the protective effect of the viscoelastics, e.g., behind the lens nucleus. Second, manipulation is easy because of the rotation and manoeuverability of the lens nucleus. These factors are central to the safety of this procedure and implicate no zonular stress, which is important for example in cases of l-week zonular fibres, such as zonular dehiscence and pseudoexfoliation.

This technique has a similar reduction in ultrasound energy to the femto-assisted phaco procedure,^6,7 which is another advantage of the technique presented here.

Last but not least, the cost/benefit ratio should be considered, which comes out in favour of our technique compared with the femtosecond laser.

Another point to consider is the rate of complications. We observed no rupture of the anterior or posterior capsule in any of our groups.

The femtosecond laser seems to be beneficial, with significantly reduced phaco time and power; further studies are needed to compare the advantages and disadvantages of each fragmentation pattern in relation to the size of the phaco tip and the system used. Our shark-tip design, which I'd like to name the ‘femtotip’, may contribute to a further reduction of the energy levels, further optimising the procedures used and perfectly restoring the vision of our patients.

References

ESCRS femtosecond laser-assisted cataract surgery (FLACS) study. Available at www.eurequo.org/new/flacs.asp [accessed 15 April 2016].
Presentation at ESCRS 2010 meeting.
D.F. Chang, ed. Phaco Chop: Mastering Techniques, Optimizing Technology and Avoiding Complications. 2004, Slack, Inc: Thorofare, New Jersey.
I.H. Fine. J. Cataract Refract. Surg. 1991; 17: 366-371.
I.H. Fine, M. Packer and R.S. Hoffman. J. Cataract Refract. Surg. 2001; 27: 188-197.
D.V. Palanker et al., Sci. Transl. Med. 2010; 2 (58): 58ra85.
M. Moshirfar, D.S. Churgin and M. Hsu. Middle East Afr. J. Ophthalmol. 2011; 18 (4): 285-291. doi: 10.4103/0974-9233.90129.

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Take-home message: IOL implantation was associated with more inflammation and slightly more visual obscuration in 120 children age 2 or younger undergoing bilateral cataract surgery. However, the rate of glaucoma was similar compared with an aphakic group.

By Vanessa Caceres; Reviewed by Abhay Vasavada, MS, FRCS

Ahmedabad, India—IOL implantation in children under the age of 2 does not always lead to a higher rate of glaucoma, but posterior synechiae can be more common, said Abhay Vasavada, MS, FRCS.

Pediatric cataract surgeons most frequently consider the safety associated with various treatments for pediatric cataract, said Dr. Vasavada, director, Iladevi Cataract and IOL Research Centre, Ahmedabad, India.

Some studies, such as the Infant Aphakia Treatment Study, have examined this topic. Though investigators have focused on unilateral cataract, there is still a need to analyze safety and outcomes in bilateral cataract.

Aphakic glasses can work well, but patients and their families are seeking alternatives.

“There’s nothing wrong with glasses, but now that lifestyles are changing, those glasses are becoming a handicap,” he said.

On the surface, it may seem that contact lenses would be another treatment option. However—contact lenses in many parts of the world are expensive and actually impractical—they need a lot of support, Dr. Vasavada said.

For these reasons, more surgeons in centers outside of the United States are considering IOL implantation. There has been some hesitation because of concern about the development of glaucoma.

Taking a closer look

In his research, Dr. Vasavada wanted to take a closer look at outcomes and safety for the treatment of bilateral cataract in patients under the age of 2. The prospective, randomized, study analyzed results for up to 5 years and looked at complications.

The study included 60 eyes with hydrophobic single-piece IOL implantation and 60 eyes with aphakia. Dr. Vasavada performed all surgeries.

To help motivate parents and their children return for numerous follow-up exams, the office helped support their travel.

The study examined glaucoma (defined as an IOP of more than 21 mm Hg), visual obscuration, and inflammation (e.g., synechiae and cell deposits).

The rate of glaucoma in the aphakic group was 16.7% and 13.4% in the pseudophakic group. Visual axis obscuration was 6.3% in the aphakic group and 10% in the pseudophakic group. Posterior synechiae occurred in 10% of aphakic patients and 25% of pseudophakic patients. There were also some cell deposits in the pseudophakic group, but they disappeared after 6 months postoperatively.

The glaucoma rate between the two groups was essentially the same, Dr. Vasavada said. However, the difference in the rate of posterior synechiae was significant.

Abhay Vasavada, MS, FRCS

E: icirc@abhayvasavada.com

This article was adapted from Dr. Vasavada’s presentation at the 2015 meeting of the American Academy of Ophthalmology. He did not indicate any proprietary interest in the subject matter.

Take-home message: Patients with accommodating IOLs implanted using a femtosecond laser-assisted procedure or manual cataract removal had similar excellent visual outcomes.

By Lynda Charters; Reviewed by Jeffrey Whitman, MD

Dallas—In the ever-expanding refractive arena, accommodating IOLs that correct both presbyopia and refractive errors are meeting patients’ high postoperative expectations by providing good vision for tasks at all distances.

Two IOLs, the Crystalens AO IOL, labeled as an accommodating IOL, and the Trulign Toric IOL (both from Bausch + Lomb), which corrects presbyopia, currently are the only such lenses that have been approved by the FDA for use in cataract surgery. While both IOLs correct presbyopia, the latter also corrects astigmatism. The Trulign IOL is not labeled as an accommodating IOL by the FDA.

The performances of the two IOLs were compared by Jeffrey Whitman, MD, in a prospective, non-randomized, two-arm study in which 100 patients received either the Crystalens AO or Trulign Toric IOL. The outcomes of the IOLs were compared based on use of a femtosecond laser platform (Victus, Bausch + Lomb) to create the primary incision and capsulotomy and for fragmentation of the nucleus or manual removal of the cataract. The patients were evaluated postoperatively at 1 week and 1 and 3 months.

The two patient groups were similar preoperatively The mean cataract grades in the femtosecond laser and manual groups were 2.2 and 2.1, respectively, and the mean patient ages were 64.7 and 61.8 years.

Refractive results

At the 3-month evaluation, Dr. Whitman, who is in private practice at the Key-Whitman Eye Center in Dallas, reported that the uncorrected distance visual acuity (UCDVA) was slightly better in the femtosecond laser group than in the manual group. The mean UCDVA levels were 20/28 and 20/30, respectively. In both groups, 28% of patients had 20/20 or better VA; 70% and 62%, respectively, had 20/30 or better; and 88% and 82% had 20/40 or better.

At the same time point, the mean uncorrected intermediate VA (UCIVA) levels were 20/18 and 20/17; 68% and 76% had 20/16 or better UCIVA; 82% and 92% had 20/20 or better; and 96% and 98% had 20/32 or better.

Finally, at the 3-month assessment, the mean uncorrected near VA (UCNVA) levels were 20/28 and 20/26; 26% and 24% had 20/20 or better UCNVA; 74% and 80% had 20/30 or better; and 94% and 96% had 20/40 or better.

The femtosecond laser group had slightly better manifest refraction spherical equivalent results compared with the manual group. Dr. Whitman reported that the respective percentages of patients who were within 0.5 D of the target were 64% and 60%, within 0.75 D 86% and 78%, and within 1 D 94% and 92%.

Based on these results, Dr. Whitman commented, “Both cohorts had an excellent combination of uncorrected distance, intermediate and near vision. There was no significant difference in the uncorrected vision between the femtosecond and manual cohorts at the 3-month evaluation. The femtosecond laser group had slightly better refractive accuracy. Additional analyses are under way to determine the time to visual stability of the UCVA and MRSE at 1 week versus 1 month.”

Jeffrey Whitman, MD

E: Jeffrey.Whitman@keywhitman.com

Dr. Whitman is a consultant for Bausch + Lomb.

Take-home message: Implantation of the newest Implantable Collamer Lens phakic intraocular lenses (V4b and V4c) did not cause cataract formation in highly myopic patients.

By Lynda Charters; Reviewed by Jose F. Alfonso, MD, PhD

Oviedo, Spain—Cataract formation has been associated with the first phakic IOLs introduced into the marketplace. However, newer models seem to be on the way to solving that problem. The latest models, the Visian Implantable Collamer Lenses (ICL) (models V4b and V4c, STAAR Surgical), did not result in cataract development in any eyes in which they were implanted.

Because ICLs meet a need in the refractive surgery arena for patients with high refractive levels, they have been gaining in popularity and not just because of their effectiveness.

In addition, they are safe, predictable, and provide stable vision for patients with high levels of myopia, hyperopia, and astigmatism.

However, the downside has been development of clinically relevant cataracts in 2.1% of patients in less than a year following implantation and in 2.7% before the 3-year mark, according to the FDA data. The culprit in the development of anterior subcapsular cataracts seems to be the contact between the phakic IOL and the natural crystalline lens.

In light of this, Jose Alfonso, MD, PhD, and colleagues, conducted a retrospective, nonrandomized, clinical study in which they evaluated the performances of three phakic IOLs, the V4, V4b, and V4c models, in 3,420 eyes of 1,898 patients who underwent surgery in one center. The mean patient age was 31.2 years (range, 18 to 50 years). The mean spherical refractive error was -7.27 (range, -26.5 to 12.5 D).

Of the 3,420 eyes, 1,531 were implanted with the V4 phakic IOL, 1,108 with the V4b model, and 781 with the V4c model. The mean follow-up times, respectively, were 6 years (range, 1 to 12 years), 2.0 years (range, 1 3o 3 years), and 6 months (range, 3 to 24 months), according to Dr. Alfonso, associate professor at the University of Oviedo, School of Medicine and head of the Cornea and Lens Department of the Fernández-Vega Universitary Institute, Oviedo, Spain.

He reported that cataracts developed in 21 (0.61%) of 15 patients with the V4 phakic IOL. No cataracts developed in eyes that received the other two phakic IOL models.

Seven (47%) of the 15 patients were younger than 40 years of age and eight (53%) were 40 years and older (mean age, 39.43 years). The mean spherical equivalent in these patients was -10.1 D. In three (14%) eyes, the phakic IOL power was less than -10.5 D, in four (19%) eyes between -10.5 and -13.5 D, and in 14 (67%) eyes higher than -13.5 D. The mean vault distance in these eyes was 103 µm. The mean time to cataract development was 4.2 years postoperatively.

The investigators published their findings in the Journal of Cataract and Refractive Surgery (2015;41:800-805).

The relationship between cataract development and vaulting has been of interest to surgeons. Previous studies have found that there is substantially less vaulting in patients who are older. A 2003 study by Gonvers and associates (J Cataract Refract Surg 2003;29:918-924) reported that central vaulting that exceeded 90 µm protects against cataract development.

However, 150 µm is recommended because of decreasing vaulting over time. In a previous study, Dr. Alfonso and colleagues reported a direct relationship between low vaulting and cataract formation, with all patients who developed cataracts having less than 100 µm of vaulting (Graefes Arch Clin Exp Ophthalmol 2010;248:1827-35).

With phakic IOLs with high refractive power, the peripheral vaulting becomes an issue in cataract development, and Dr. Alfonso advised surgeons to consider this in patients who are highly myopic.

In addition, patient age seems to be a factor in cataract formation, with older patients developing cataracts more often than younger ones. Dr. Alfonso has no financial interest in this subject matter.

In the study under discussion, the authors concluded, “…implantation of the [ICL] phakic IOL led to a very low incidence of cataract formation. The prevalence of cataract was higher in patients who were older, had high refractive errors, and had older phakic IOL models.”

Jose F. Alfonso, MD, PhD

E: j.alfonso@fernandez-vega.com

Dr. Alfonso did not indicate any proprietary interest in the subject matter.

Take-home: Reverse optic capture may be a viable option for addressing a decentered single-piece IOL as the result of a compromised posterior capsular or a posterior capsular tear.

Reviewed by Richard S. Hoffman, MD

Eugene, OR–All surgeons, no matter how experienced, encounter tough cases that require creative approaches.

Richard Hoffman, MD, described such a patient with a 2+ nuclear sclerotic cataract that he removed using a standard bimanual technique, which progressed routinely.

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Dr. Hoffman used a horizontal chopping technique to remove the nucleus and filled the capsular bag with a cohesive viscoelastic (OVD). The anterior capsulorhexis and posterior capsule were intact.

Dr. Hoffman, clinical associate professor of ophthalmology, Oregon Health & Science University, Eugene, OR, injected a single-piece hydrophobic acrylic IOL into the bag. The haptics were covered with polymethylmethacrylate mittens to prevent them form sticking to the optic.

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During the centering of the IOL, a crease in the posterior capsule was visible. Dr. Hoffman hypothesized that it was a zonular dialysis with a wrinkled bag that might resolve with gentle pushing down on the IOL. Repeated pushing did not reach the desired end.

Since the lens was centered, Dr. Hoffman started to remove the OVD. In doing so, the IOL began to shimmy and vitreous was visible in the aspirating cannula. The IOL appeared slightly tilted and moved down toward what Dr. Hoffman described as an obvious opening in the equator of the bag.

Surgical options

The surgical options for a torn posterior are:

Leave the IOL in place and address it if it subluxates further;
Levitate the IOL into the ciliary sulcus (not an option for a single-piece IOL);
Levitate the IOL into the ciliary sulcus and suture the haptics (also not a viable option);
Use the capsulorhexis to capture the optic;
Exchange the IOL for a three-piece IOL in the sulcus

Performing a reverse optic capture

Dr. Hoffman opted to perform a reverse optic capture. He first injected an OVD in front of the lens and more behind the lens to push the vitreous back behind the capsule. He then used the same viscoelastic cannula to prolapse the optic up in front of the anterior rhexis, which proved to be successful.

“At this point, the IOL was centered and stable,” Dr. Hoffman commented.

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Because vitreous was in the anterior chamber previously, Dr. Hoffman removed the OVD using a 23-gauge vitrector. A 20-gauge irrigating cannula was positioned through the left-hand incision. Hindsight suggested that a 20-gauge vitrector would have prevented fluid from egressing from the bimanual incision.

After removing as much of the OVD as possible, Dr. Hoffman removed the vitrector and kept the irrigator in the eye. He injected triamcinolone to identify any vitreous in the anterior chamber, and used the irrigator to wash the triamcinolone out of the eye.

When no vitreous was seen in the anterior chamber, Dr. Hoffman hydrated the incision and kept the irrigator in the eye to maintain the pressure and prevent vitreous from coming from around the lens.

“The reality was that with the optic captured on the rhexis, even if the chamber did become shallow, additional vitreous probably would not have come forward,” Dr. Hoffman said.

He finished the surgery by hydrating the wounds, removing the infusing cannula, and injecting Miochol-E (acetylcholine, Bausch & Lomb) into the anterior chamber.

Three months postoperatively, the IOL remained centered. OCT showed good clearance between the anterior surface of the IOL and the posterior surface of the iris.

Considerations

Considerations

Dr. Hoffman noted that the Cataract Clinical Committee of the American Society of Cataract and Refractive Surgery has emphasized that single-piece IOLs should not be implanted into the ciliary sulcus without fixation because of the risk of pigment dispersion, glaucoma, uveitis, and recurrent vitreous hemorrhages.

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“However, it may be OK to put single-piece IOLs in the bag and perform reverse optic capture,” said Dr. Hoffman, recounting a recent study of the procedure performed in 16 eyes, with 12 of the fellow eyes serving as controls (Ophthalmic Surg Lasers Imaging 2012;43:480-8).

The authors reported that patients achieved 20/25 or better vision in 94% of the eyes in which the reverse optic capture was performed compared to 92% in the control eyes. In both groups, 94% and 100%, respectively, were within 1 D of the intended correction. The IOLs in all eyes that underwent reverse optic capture remained centered, and no vision-threatening complications occurred after 19 months of follow-up.

The study concluded that reverse optic capture of a single-piece acrylic IOL through an anterior capsulorhexis merits consideration for IOL placement in selected cases of insufficient posterior capsule support.

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Richard Hoffman, MD

e. rshoffman@finemd.com

This article was adapted from a presentation Dr. Hoffman made at the 2015 American Academy of Ophthalmology meeting. He has no financial interest in any product mentioned in this report.

Take-home: An approach is described for completing cortex removal and IOL implantation after intraoperative 180° zonular dialysis.

Reviewed by Iqbal (“Ike”) Ahmed, MD

Toronto—When an overly aggressive attempt to remove tenacious cortex results in iatrogenic zonular dialysis, the first priority for the cataract surgeon is to maintain capsule integrity and avoid vitreous prolapse. Removal of residual cortex is also important for the final outcome.

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Options for management might include cautious endocapsular phacoemulsification, conversion to extracapsular surgery, capsular retractors, implantation of a capsular tension ring (CTR), and use of a sutured capsular tension device, reported Iqbal (“Ike”) Ahmed, MD. The decision, however, is best made through careful assessment of the situation once the eye is stabilized.

Dr. Ahmed, assistant professor of ophthalmology and vision sciences, University of Toronto, Ontario, Canada, presented his approach to managing this “disinsertion dilemma” in a case involving a 180° zonular dialysis.

The patient did not have pseudoexfoliation or other risk factors for zonular weakness, and the surgery was uneventful until cortex removal. As the operating surgeon persisted in trying to remove residual cortex, the capsule was aspirated into the instrument tip, resulting in 180° of nasal zonular dialysis with retained cortex in the capsular bag. Fortunately, the capsular bag remained intact, Dr. Ahmed said.

Injecting OVD

After stopping the procedure and while keeping the I/A tip in the eye, a cohesive ophthalmic viscosurgical device (OVD) was instilled to reform the anterior chamber and stabilize the eye.

Dr. Ahmed offered several tips for completing this initial step.

“It is important to keep the I/A instrument in place because if the capsule has been aspirated into the tip, removing the hand piece from the eye could bring the entire capsular bag too,” Dr. Ahmed said.

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The injected OVD can displace any aspirated capsule from the tip, but before OVD is injected, infusion should be stopped or the OVD will come back out from the incision site. At the same time, surgeons should not overfill the eye–as that also will cause OVD to leak out of the incision, and vitreous prolapse may follow.

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Once the I/A tip is freed of material and the chamber stabilized, examination showed the residual cortex present in the superior area of the capsular bag, well away from the site of the zonular dialysis. Considering that use of an automated technique for completing cortex removal could create an unstable situation, Dr. Ahmed chose a manual approach to cortex aspiration, using a 27-gauge hockey stick cannula to irrigate and aspirate the residual cortex.

“It is important to add a few boluses of irrigation that will not only help with cortex removal but will also keep OVD away from the cannula,” he said.

Comfort level for CTR

Comfort level for CTR

After completing cortex removal, Dr. Ahmed said he was comfortable placing a CTR to stabilize the capsular bag in this case, taking into account the location of the zonular dialysis, its extent, and anticipating that it was stationary, i.e., non-progressive.

“My limit for using a standard CTR is up to six clock hours of localized zonulysis, assuming the remaining zonules are in good shape,” Dr. Ahmed explained. “In that setting, the CTR is quite effective in distributing forces around the entire capsular circumference.

“In addition, the dialysis in this eye was 180° away from the incision, which enabled injection of the CTR into the area of weakness,” he added. “That would have been more difficult if the dialysis was located temporally.”

Dr. Ahmed removed cortex first rather than starting with placement of the CTR—as the latter sequence could result in trapping cortex behind the ring.

Dr. Ahmed then implanted a one-piece IOL, which he favored because its insertion is atraumatic relative to a three-piece implant. OVD was removed manually due to concern over the possibility of bringing vitreous forward using the I/A hand piece in an automated technique.

“The outcome seemed favorable, although I felt if the lens decentered, I could still go back in the first few months postoperatively to suture the CTR to the sclera and avoid a more extensive secondary procedure in the OR,” said Dr. Ahmed. “Fortunately, the IOL has remained well-centered.”

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Ike Ahmed, MD

e.ike.ahmed@utoronto.ca

This article is based on a presentation given by Dr. Ahmed at the 2015 American Academy of Ophthalmology meeting.

Dr. Ahmed is a consultant to Abbott Medical Optics, Alcon, and Bausch + Lomb.

Take-home: Cataract surgery technology continues to advance with improvements that enhance surgical performance every step of the way.

Reviewed by Robert J. Weinstock, MD

Largo, FL––No matter how advanced a technology becomes, nothing is perfect. The same holds true for cataract surgery technology. There are other complementary tools for femtosecond lasers that are available, which will help surgeons achieve better outcomes for their patients.

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Femtosecond laser cataract surgery has successfully furthered the subspecialty, most notably because it is safer and a more precise method than the manual procedures with the use of arcuate incisions, creation of capsulotomies, and nuclear disassembly.

The missing links

Despite the advancements, there are some technologies are beginning to hot the market, according to Robert Weinstock, MD, who is in private practice in Largo, FL. He pointed to automation, integration, and surgical guidance to help with the throughput of cataract surgery, surgical planning, and the execution of refractive targeting and refractive outcomes.

“We need more surgical planning software that is associated with the lasers to help in the choice of intraocular lenses (IOLs) and the surgical plan for cataract removal and astigmatism treatment and to help free patients from spectacle dependence,” Dr. Weinstock said.

Another area is iris registration. The software for creation of arcuate incisions is becoming available. Software should also customize the laser treatments depending on the density of the lens and the size of the cataract. Surgical field navigation and guidance would provide on-screen navigation to help guide maneuvers, Dr. Weinstock explained.

“We currently are moving toward a surgical navigation concept to use guidance for placing the incisions, capsulotomies, and limbal-relaxing incisions and for selecting toric IOL powers and positioning of the lenses, and IOL centration,” he pointed out. “These are all critical parts of cataract surgery that need to be worked on.”

New technologies that are now incorporated into the lasers include automated registration and treatment plans, cataract grading, and customized fragmentation patterns. Advances introduced into phacoemulsification include surgical cockpit setups with information projected through ocular microscopes or on a three-dimensional guidance screen, all of which, Dr. Weinstock said, will help surgeons perform better surgeries.

The postoperative regimen also will benefit from advancing technologies that provide automated refraction, imaging, and feedback into planning software that drives the nomograms and improves outcomes, he noted.

Some advancements

The LENSAR laser provides streamline iris registration for placing limbal-relaxing incisions and intrastromal marks. Dr. Weinstock explained how the laser uses an image of the undilated pupil and an image of the unwound iris for iris registration. The two images are lined up during the laser treatment and a shift is done to move the arcuate incisions to account for cyclotorsion and head tilt.

The laser can image the nucleus and do automatic nuclear grading and density, based on Scheimpflug imaging, to guide various treatments and the sizes of the laser treatments. After the nuclear imaging, the iris registration occurs and the laser treatment is applied accordingly.

The technologic advances are invaluable. In one such case, Dr. Weinstock described, there was 17º error in cyclorotation. “In patients with larger degrees of astigmatism, if the cyclorotation error and head tilt are not considered, the limbal-relaxing incisions will be placed incorrectly,” he said. “This software is desperately needed to improve our outcomes with limbal-relaxing incision.”

Programmable pattern selection software, also in the LENSAR laser, describes the grade and density of the cataract. “The surgeon can program the laser to perform a simple fragmentation pattern for a soft lens or a more robust matrix or cube pattern for a denser cataract. This can be automated by the laser rather than being decided manually,” he said.

The Verion Image Guided System with the LenSx laser (Alcon Laboratories) has features that are similar to those of the LENSAR laser. The features of the system include a preoperative diagnostic device that obtains an infrared image, a planning software station, the laser, and intraoperative guidance. The images obtained show the position of the capsulotomy, the optimal position for a multifocal optic, and a toric IOL.

Intraoperative aberrometry

The ORA (Alcon Laboratories) and Holos IntraOp (Clarity Medical Systems) are the two units that are commercially available.

The ORA, which is familiar to most surgeons as part of the Verion system, is excellent for determining aphakic power selections for monofocal, presbyopic-correcting, and toric IOLs, Dr. Weinstock said. It performs a pseudophakic measurement and advises the surgeon when the IOL is in the correct position and axis.

Dr. Weinstock added that the ORA provides improved refractive outcomes in well-documented published studies.

The newly released Holos IntraOp is similar to the ORA and provides similar measurements. Studies are currently under way to evaluate the performance of the instrument compared to ORA. “I am sure it will achieve the same goals for our patients,” Dr. Weinstock said.

The Callisto (Carl Zeiss Meditec) and the TrueVision 3D Surgical system (TrueVision Systems) are two other devices used to facilitate intraoperative surgery. Dr. Weinstock commented that the resolution of the screen and camera of the TrueVision are so advanced that the microscope oculars are unnecessary.

“The surgeon can sit in a comfortable position, wear 3D glasses, look at the screen, and operate directly off of it,” Dr. Weinstock said. “I operate heads up off a screen on all cataract surgeries without looking through a microscope. This is the future of cataract surgery.”

A surgical cockpit setup allows the integration of other platforms to visualize, for example, ORA on one side of the screen and the eye on the other side. This allows the surgeon to see all needed information on one screen rather than looking away at another separate screen.

Other systems

Bausch + Lomb is developing the Spectrus unit, which is another intraoperative guidance system that is similar to the Callisto.

“Cataract surgery continues to evolve,” Dr. Weinstock concluded. “The femtosecond laser is not the only component of interest regarding the outcomes. All of these devices are helping to achieve better outcomes for our patients. All technologies must continue to be safety-and-outcome driven.

“Automation with lasers and guidance is the future of cataract surgery. The devices need to be integrated so that the procedure is more seamless and there is better throughput in the operating room. However, attention must be paid to efficiency, economy of scale, and cost effectiveness,” he added.

Robert J. Weinstock, MD

e. rjweinstock@yahoo.com

Dr. Weinstock is a consultant for Bausch + Lomb, Alcon Laboratories, and LENSAR. He receives honoraria from Alcon Laboratories and Bausch + Lomb; and has ownership interest in TrueVision.

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