ASCRS [logo] SAN FRANCISCO — Accommodative IOLs and customized ablation were two of the main topics of interest at this year’s American Society of Cataract and Refractive Surgery meeting.

This year’s meeting offered more than twice as many presentations on accommodative IOLs than last year’s meeting.

Notably, since the time of last year’s ASCRS meeting, Alcon’s LADARVision system received regulatory approval for performing wavefront-customized ablation. The fact that this technology is now available to practitioners – and that other companies’ technologies are expected to be approved soon – heightened attendees’ interest in what custom ablation can achieve.

Other IOL technologies for both cataract and refractive surgery — including phakic IOLs, ultrathin designs and light-adjustable materials — also attracted much attention.

Attendance was up slightly over the 2002 meeting, despite the conflict in Iraq and fears regarding severe acute respiratory syndrome (SARS). ASCRS officials estimated that registration for medical personnel was nearly 6,200.

Other highlights of the meeting follow. Many of these items appeared previously on PCONSuperSite.com as part of our daily coverage from the meeting. Note that this article is not meant to be an all-inclusive representation of the ASCRS meeting, but rather a sampling of some of the interesting presentations.

Leaming: Cataract up, LASIK steady

Cataract surgery volume rose in 2002, while LASIK volume remained relatively steady, according to the 2002 Leaming survey. This may signal a reversal of the trends seen in the late 1990s, when cataract surgery volume decreased slightly and LASIK volume skyrocketed.

At the meeting’s opening session, David V. Leaming, MD, presented the results of his annual Practice Styles and Preferences of U.S. ASCRS Members. He said LASIK volume rapidly expanded in the late ’90s, with almost 1 million procedures performed in 2000, then growth began to drop off in 2001. Currently, volume seems to have leveled off.

“You can look at this another way,” he said. “The rate of growth was greatest in 1997 and 1998. It dropped in half the next year, and then again in half the next year. And then in 2000 and 2001 it was down 12%. [Currently], LASIK growth [is] essentially flat, although the number of ophthalmologists performing LASIK also declined. So those who are still doing it have picked up a little volume.”

The results were based on an 18% response rate to 5,800 questionnaires mailed to the U.S. members of ASCRS.

Use of antibiotics in cataract surgery irrigating solution has declined slightly, from 34% to 27%.

Regarding choice of IOL material, 63% of respondents reported preferring acrylic IOLs. Silicone ranks second, with about 25% of respondents choosing that material. Those results have stayed fairly constant during the past 3 years, Dr. Leaming said.

The majority of respondents said they would perform phaco alone in a cataract patient with well-controlled glaucoma. In patients with poorly controlled glaucoma, however, respondents said they would prefer performing phaco with antimetabolite trabeculectomy, followed by phaco with trabeculectomy as a second choice.

Use of a prostaglandin as first-line glaucoma therapy increased 36% over 2001, with Xalatan (latanoprost, Pharmacia) as the most prescribed medication. Lumigan (bimatoprost, Allergan) was second, at 19%, and other drugs ranged from 17% to 6.3% in preference.

Prednisolone was the preferred anti-inflammatory agent for both cataract and refractive surgery, followed by fluorometholone (FML, Allergan) in refractive surgery. The preferred antibiotic was Ocuflox (ofloxacin, Allergan) for both cataract and refractive surgery, followed closely by Ciloxan (ciprofloxacin, Alcon) and Quixin (levofloxacin, Santen).

New president introduced

Also in the opening session, Stephen S. Lane, MD, was introduced as the incoming president of ASCRS. Dr. Lane was one of the early clinical investigators of the excimer laser, and he has been performing refractive surgery for more than 15 years. Dr. Lane accepted his presidential medal from the outgoing ASCRS president, Marguerite B. McDonald, MD.

Accommodating IOLs at 2 years

New president: Marguerite B. McDonald, MD, outgoing ASCRS president, congratulates Stephen S. Lane, MD, on his new role.

Patient motivation is a key factor in the success of accommodating IOLs, according to a surgeon who has been implanting the lenses for more than 2 years.

“The magnitude of accommodative power is greater if the patient is motivated to use it,” said Tobias Neuhann, MD. He described his long-term experience with the C&C Vision CrystaLens here.

Dr. Neuhann began implanting the C&C Vision lens in July 2000, and he now has 14 patients with more than 19 months’ follow-up. Accommodative amplitude in these patients ranges from about 1.5 D to 3 D at most recent follow-up, he said.

Initially, Dr. Neuhann said, patients tend to have a high degree of accommodation, but at 3 months the amplitude begins to decrease somewhat. He said when he first noted this phenomenon, he felt the accommodative IOL was failing. In response, Dr. Neuhann said he prescribed the standard 2.5 D spectacle add for these patients, and at 1 year their accommodative performance was relatively poor.

But he said he has since discovered that a smaller degree of spectacle add – or none at all – is enough for most of his accommodative IOL patients to see well at distance and near. “If patients are motivated to use their accommodation, they will use it,” Dr. Neuhann said. “The add required for most patients to achieve Jaeger 1 is about 1 D to 1.5 D.”

Dr. Neuhann said that at 2 years, binocular near vision of J2 can be achieved by almost 100% of patients with their distance correction in place. “Our results at 2 years are much better than at 1 year,” he said.

High satisfaction with ICL

Stephen G. Slade, MD, presented 3-year follow-up interim results for STAAR Surgical’s Implantable Contact Lens (ICL) for myopia. The results represented a 36-month follow-up after the ICL was implanted in 369 eyes.

Dr. Slade, an investigator of the STAAR ICL, said 38% of patients gained one line on a standard eye chart of best-corrected visual acuity, and 10.8% gained two or more lines. Mean level of preop myopia was –10.12 D. Ninety-five percent of the patients with good preoperative visual acuity targeted for emmetropia had uncorrected visual acuities of 20/40 or better; 57% had uncorrected visual acuities better than their best-corrected visual acuity preoperatively.

He also said the procedure demonstrated less than 0.1 D change in result from 1 week postoperative to 36 months postoperative. Regarding predictability, 68% of patients were within 0.5 D of attempted correction, 88% were within 1 D and 98% were within 2 D.

Toric AcrySof stays stable

A new toric IOL is showing good rotational stability in clinical trials to date. Stephen S. Lane, MD, the medical monitor for trials of the Alcon AcrySof Toric Single-Piece IOL, described results of the trials here.

Dr. Lane said the shrink-wrap effect that has been noted with earlier non-toric versions of the AcrySof seems to help keep the new toric lens rotationally stable. He noted that rotation of a toric IOL by as little as 30° can cancel out the astigmatic correction built into the lens.

The modified L-shaped haptics of the IOL help keep it in position despite the forces of capsular contraction, he said.

Dr. Lane said that in the clinical trials of the AcrySof Toric to date, more than 60 lenses have been implanted, with follow-up of at least 60 to 80 days.

At postop day 1 or 2, all lenses were within 10° of intended axis, and in fact nearly all were right on the proper axis, he said. At the 60- to 80-day visit, there was almost no rotational movement.

Although he is medical monitor of the AcrySof Toric study, Dr. Lane noted that he has no direct financial interest in the device.

Adjustable IOL

Technology used in customized ablation may be copied in IOLs to allow adjustment of the lens inside the eye, according to one presenter.

John Hunkeler, MD, spoke about PowerVision’s power-adjusting lens, now in development, which theoretically can be corrected for defocus error and higher-order aberrations using a pixilated actuator. Piston-driven actuators are individually adjusted, and the optical thickness of the lens is manipulated at multiple locations to adjust the local power of the lens surface.

The lens is irradiated by this pixilated actuator around its edge to correct for myopia or astigmatism, Dr. Hunkeler said. Because the lens has a layer of fluid cells in its center, the surgeon can potentially repeat the process as often as needed as the patient’s eye changes.

The lens will be entering animal studies in the near future, Dr. Hunkeler said.

Wavefront analysis of Tecnis

The Tecnis IOL seems to correct the spherical aberration in the eye’s optical system, according to a study using wavefront analysis.

Roberto Bellucci, MD, of Verona, Italy, described a study he performed comparing several types of IOLs using the Topcon Wavefront Analyzer, which measures both wavefront characteristics and corneal topography simultaneously.

The 25 patients in the study were implanted in equal numbers with one of five types of IOL: the Tecnis, the 911 Edge or 812 C from Pharmacia, or the one-piece or three-piece AcrySof from Alcon.

Dr. Bellucci explained that the output of the Topcon device shows both corneal spherical aberration and the total spherical aberration of the eye’s optical system, so it is possible to calculate how much of the aberration is produced by the lens. He said total spherical aberration was reduced by the Tecnis and increased by all the other IOLs studied.

Dr. Bellucci acknowledged a financial interest in his subject matter.

ClariFlex in high-risk eyes

The ClariFlex IOL is highly biocompatible and well tolerated in eyes at high risk for glaucoma, according to Thomas W. Samuelson, MD, of Minneapolis.

Dr. Samuelson presented results of a study he conducted with Elizabeth A. Davis, MD. The prospective study included 105 eyes of 120 patients implanted with the AMO ClariFlex IOL following phacoemulsification. All eyes had been diagnosed with glaucoma, and all patients were receiving medical treatment alone or with previous surgical treatment.

Dr. Samuelson acknowledged a financial interest in his subject matter.

Not for everyone

Wavefront technology allows the surgeon to customize refractive surgery, but “the right thing to do is not to do it for everyone because not everyone is a good candidate,” said one speaker. “The more higher-order RMS a patient has preoperatively, the more beneficial wavefront can be for them,” said Louis Probst, MD. Dr. Probst has been performing customized refractive surgery for several years in Canada.

“Patients are overwhelmed by this technology, and you must manage the patient’s expectations,” he said. Dr. Probst charges patients about $500 more per eye for wavefront-guided surgery. Attempts to charge more than that were unsuccessful, he said.

Dr. Probst said he has been impressed with the best-corrected visual acuity results of the Zyoptix wavefront-guided ablation system from Bausch & Lomb, with which 92% of his patients have achieved 20/20 postop.

Dr. Probst also spoke about several other emerging refractive technologies – the IntraLase Pulsion FS laser, the Refractec Viewpoint CK system for conductive keratoplasty and the Anamed Permavision stromal implant.

The IntraLase laser, which can be used for flap creation in LASIK, is “making an impact and will have increased influence in the market in the next few years,” he said. He noted, however, that there have been anecdotal reports of flap slippage that may be detrimental to the success of the IntraLase, and he warned practitioners to be prepared to spend more than $1 million for the laser.

Dr. Probst suggested people interested in the Viewpoint CK system go to the Food and Drug Administration’s Web site, where they can analyze the data objectively, including the complications reported with the system.

“CK does not have the amount of regression to concern the FDA, but it seems to me there’s a consistent regression pattern with it,” he said. Extrapolating current regression trends, he said some patients might fully regress in about 42 months. Another concern with the technology is induced astigmatism, “in some cases by several diopters,” he said.

Anamed’s Permavision stromal implant is an additive, reversible procedure that offers stable results for the patient, Dr. Probst said. “There’s a great potential with this technology for pediatric refractive surgery. There are some real applications here for hyperopia, but there are some reports about fibrous haze around the implants, so it may not be as biocompatible as we’d like to see,” he said.

Shortcomings of wavefront

Until certain fundamental issues are resolved, wavefront customized ablation will not live up to heightened expectations, said refractive surgeon and optics expert Jack T. Holladay, MD. Several inherent problems with the technique will for the time being prevent wavefront from becoming the laser technique of choice for most surgeons, Dr. Holladay said.

First, he said, wavefront-guided lasers have not compensated for oblique incidence of light on the cornea. The result of this is that the cornea becomes oblate, when it should be prolate, he said.

A second inherent problem he noted is that the wavefront-guided laser must be perfectly aligned or else the off-axis corrections will not work. “When you correct lenticular aberrations on the cornea, it creates an ‘extreme’ on-axis system. (The laser) is not lined up for off-axis images,” he said.

Further, direct correction of the eye with wavefront “assumes the path through the crystalline lens is the same,” Dr. Holladay said. “Actually, the rays pass through different locations in the crystalline lens, introducing different aberrations.”

The flap created during LASIK can also induce its own series of aberrations, such as astigmatism and higher-order RMS error, he said.

Wavefront-guided correction is also limited by the characteristics of the tracking system used. “You must have absolutely perfect fixation, which is not possible at this point,” he said.

Finally, Dr. Holladay said, contrast sensitivity should be the primary measure of visual performance, but it is impossible to gauge true contrast sensitivity after wavefront surgery because it always declines postoperatively. “So far, custom ablation studies do not show improvement in (contrast sensitivity),” Dr. Holladay said.

Age and higher-order aberration

The magnitude of higher-order aberrations varies greatly among patients in the general population and increases only slightly with age, according to one surgeon.

Douglas D. Koch, MD, examined higher-order aberrations using the Visx WaveScan system across a 6-mm pupil in 532 eyes of 306 patients ranging in age from 20 years to 71 years (mean age 41 years).

Patients in the study had a mean spherical equivalent of –3.39 D, and none of the eyes had had previous refractive surgery. No eyes were pharmacologically dilated.

Dr. Koch said the average of the Zernike coefficients centered around zero for the overall population. The main exception was the third-order terms of trefoil and spherical aberration.

“There’s a big standard deviation. But the mean tends to be relatively low,” Dr. Koch said. “On the other hand, if you look at the mean absolute values, you get a much different sense of things. And as you might anticipate, the third-order terms are the greatest, and the fourth order, the spherical aberration term, had a tendency to diminish.”

The mean RMS values for the higher-order aberrations was 0.305 ± 0.095 mm, 0.128 ± 0.074 for spherical aberrations and 0.17 ± 0.089 for coma.

In addition to higher-order aberrations, Dr. Koch also looked at mirror symmetry between the right and left eyes of the individual patients. He noted that significant correlations were found between the right and left eyes (P < .001), with a Pearson correlation coefficient of r = 0.601 for higher-order aberrations, r = 0.776 for spherical aberrations and r = 0.511 for coma.

The strongest correlation was for fourth-order spherical correlation, r = 0.836 between the eyes.

Pediatric IOLs vs. contacts

Pediatric cataract surgery patients with IOLs implanted had superior binocularity but similar visual acuity to patients with contact lenses after cataract surgery, one surgeon said.

Arun Samy, MD, presented a study comparing visual acuity and binocularity outcomes in cataract patients younger than 48 months of age. The mean age of patients at the time of diagnosis was 7.1 months for the contact lens group and 18.3 months for the IOL group. The mean patient age at time of cataract removal was 20.6 months in the IOL group and 8.5 months for the contact lens group.

Dr. Samy said mean follow-up for the IOL group was 77.5 months and for the contact lens group 68.5 months.

Patients in the IOL group had better binocularity outcomes than those in the contact lens group. Of the IOL patients, 77% were in the positive binocularity group vs. 37% in the contact lens group.

New antibiotics fight endophthalmitis

Newly approved fluoroquinolones will be an important component in reducing the incidence of endophthalmitis, according to a group of surgeons speaking here. Allergan’s Zymar (gatifloxacin ophthalmic solution 0.3%) was the subject of a panel discussion at the company’s booth during the meeting.

Zymar has shown promise in treating bacteria that are demonstrating increasing ocular resistance, the surgeons said. The resistant bacteria are, in large part, responsible for an increasing incidence of endophthalmitis on a global scale.

“Because of the resistance, we are seeing more endophthalmitis and more infections with clear corneal incisions,” said Stephen Pascucci, MD.

Zymar’s ability to penetrate deep within the eye and its dual mechanism of action will help combat atypical mycobacteria that can cause endophthalmitis. Previous iterations of fluoroquinolones do not have the same effect on this kind of atypical mycobacteria, the surgeons said.

“If I want something that targets specifically atypical mycobacteria, I want [gatifloxacin],” said Ralph Chu, MD.

The surgeons agreed that gatifloxacin increases coverage of Streptococcus pneumoniae, methicillin-resistant Staphylococcus aureus, S. epidermis and atypical mycobacteria, while decreasing phototoxicity and ocular resistance.

Randall Olson, MD, said now is the opportune time for surgeons to begin using Zymar. “There is often a tendency to want to reserve the big guns. But here we’re better off switching rapidly to [these fluoroquinolones] because we’re right at the curve where resistance is becoming a major problem,” Dr. Olson said.

Zymar was granted U.S. marketing approval for the treatment of bacterial conjunctivitis caused by susceptible strains of bacteria at the end of March. A little more than 2 weeks later – on the last day of the ASCRS meeting – a rival fluoroquinolone, Alcon’s Vigamox (moxifloxacin ophthalmic solution 0.5%), also received regulatory approval.