VA high quality, complications low with phakic IOL

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1 Page 1 of 5 VA high quality, complications low with phakic IOL Use in keratoconus will continue, one surgeon predicts; another ponders long-term safety Nov 1, 2007 By:Nancy Groves Ophthalmology Times Several surgeons reviewed their experiences and study results with an implantable contact lens ([ICL]; Visian Implantable Collamer Lens, STAAR Surgical), presented long-term results from phakic IOL implantations performed a decade or more ago, and compared complication rates between ICL implantation and laser vision correction in a series of presentations at the annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS), San Diego. The ICL discussed provides excellent visual results for correction of myopia Dr. Boxer Wachler in healthy eyes and also benefits patients with keratoconus, said Brian S. Boxer Wachler, MD, Boxer Wachler Vision Institute, Beverly Hills, CA. He presented results with the lens in a sequential series of patients, both in healthy eyes and those that had keratoconus, since the implant received FDA approval in late "This lens certainly has the ability to produce extremely high-quality vision because it's flirting with the nodal point. It has the potential to be extremely accurate despite high myopia levels of correction," he said. "The use in keratoconus is going to continue as more cases are done showing that it results in significant improvements in best-corrected vision." According to Dr. Boxer Wachler, it is possible to get extremely close to the nodal point, which is the best optical position of any corrective lens in the eye, with this phakic IOL. "We can potentially get higher-quality vision by moving closer to the nodal point," he said. "Especially in a keratoconic eye, if we put the myopia correction behind the distorted, abnormal, keratoconus cornea, maybe we have an even greater benefit by being closer to the nodal point in those patients." Dr. Dulaney

2 Page 2 of 5 The post-fda series Dr. Boxer Wachler described included 31 eyes in healthy patients; their average age was 38 years, and their average myopia was about 11 D, with a range of 3.5 D (this patient had forme fruste keratoconus) to 19 D. All patients had more than 1 month of follow-up. The cohort also included five eyes with keratoconus and with similar demographics. Most cases were performed bilaterally with separate drape and gown for each eye. Results in the healthy-eye group showed that uncorrected monocular visual acuity was 20/20 in 44% of eyes and 20/16 in 8% of them. Binocular vision results: 20/20, 80%; 20/25 or better, 100%; and 20/16, 20%. All patients had preoperative best spectacle-corrected visual acuity (BSCVA) of 20/25 or better. "Because of the summation effect in visual acuity, we get a functional improvement with binocular vision compared with one eye at a time," Dr. Boxer Wachler said. Most patients had no change in best-corrected visual acuity (BCVA), and none lost 1 line or more; 26% gained at least 1 line of vision. Outcomes also indicate that the procedure was highly accurate; the mean correction was about 0.4 ± 0.39 D, and the mean standard deviation was Dr. Vukich about 0.4 D as well. Several of the eyes with keratoconus also gained BCVA, which reaffirms the idea that working close to the nodal point will improve visual acuity, although in this group residual refractive error will remain, Dr. Boxer Wachler said. Complications are possible with any intraocular procedure, he noted, but in this series no cataracts, increases in IOP, pupillary block, pigment dispersion, infection, non-patent peripheral iridectomy, or re-operations were seen. FDA 5-year follow-up Another clinician reported the outcomes of the FDA clinical trial of the ICL with 5-year follow-up. BSCVA was 20/20 or better in 50% of patients and 20/40 or better in more than 90%, said John A. Vukich, MD, clinical assistant professor, Department of Ophthalmology, University of Wisconsin School of Medicine, Madison. "We believe that the effectiveness data at 5 years post-op establishes the effectiveness of the myopic ICL for correction of 3 to 20 D. Clinical outcomes also substantiate the overall safety of the myopic ICL in this moderate-to high-myopic population," Dr. Vukich said. Dr. Zaldivar He and colleagues treated the patients in this cohort during the 3-year FDA trial and have continued to follow them to accumulate long-term safety and effectiveness data. "I don't think anyone doubts the ability of the lens to correct a refractive error; the real issue with all phakic IOLs is going to be long-term safety, not the efficacy as much. We're all confident with that," Dr. Vukich said. The 3-year data reported on 526 patients; 384 patients have been followed for more than 4 years, and 311 have been followed for more than 5 years. Uncorrected visual acuity (UCVA) at 5 years for eyes with a preoperative BSCVA of 20/20 or

3 Page 3 of 5 better showed that 57% maintained the ability to see 20/20 and 78% had a 20/25 acuity level. In patients in which postoperative UCVA was equal to or better than preoperative BSCVA, some additional myopic drift occurred after the first year in that a few patients were no longer able to see equal to or better than their preoperative BSCVA, Dr. Vukich said. In this subgroup, postoperative acuity was 20/20 or better in 50.9% and 20/40 or better in 91.7%. The results for attempted versus achieved correction at 5 years showed that 62% of eyes were within 0.5 D and 85.5% were within 1 D. "As we might expect, there is really no reason to believe that this would be unstable over time in terms of the power of the lens, but it's interesting that these patients did maintain a very stable correction and remained at about 0.5 D, which is in fact identical to what they were at 12 months," Dr. Vukich said. "We saw no myopic drift or change in the average mean spherical equivalent at 5 years." In many patients, an initial gain in BSCVA at distance was sustained over the 5-year period; 95.5% maintained a BSCVA level of 20/25, and 84% maintained acuity of 20/20 or better. The mean change in BSCVA from preoperative acuity was slightly more than half of a line. Regarding the mean change in BSCVA preoperatively to 5 years, 40% maintained a 1-line improvement, 5% lost 1 line, 7% gained 2 lines, 0.9% lost 2 lines, and 42% had no change. Patient satisfaction data at 4 years showed that 100% were pleased with the quality of their visual acuity, Dr. Vukich said. This result was consistent over the first 4 years but was not assessed at year 5; patient surveys will again include this question at the 6-year follow-up. The rate of clinically significant cataract formation was 1.3% at 5 years; the rate of asymptomatic anterior subcapsular opacities was 4.6%. Dr. Vukich reported a significant difference in the incidence of cataract, based on preoperative myopia and said he now is considering segregating patients based on whether their pre-existing myopia is less than or greater than 12 D. In this study, no cataracts developed in individuals whose preoperative myopia was less than 12 D. An age variable also was significant in the rate of clinically significant cataract. Only one patient who was aged fewer than 40 years at the time of implantation has developed a change in the lens; the other six patients who developed cataracts were aged more than 40 years when the procedure took place. "We are certainly following this carefully but believe that the robustness of the human crystalline lens or the ability to tolerate the implantation may be less as patients are more mature," Dr. Vukich said. No new complications other than a cataract have occurred since 3-year data were submitted to the FDA for approval, he said. Early cases Roberto Zaldivar, MD, director of the Instituto Zaldivar, Mendoza, Argentina, also reported longterm results of implantation of ICLs. He implanted a number of the first-generation ICLs in 1993 and 1994 and has follow-up data from 9 to 13 years on 31 of his early cases. IOP, the stability of the correction, and visual acuity are the parameters to monitor during follow-

4 Page 4 of 5 up, according to Dr. Zaldivar. In this group of patients, the long-term results show that IOP changed little from the preoperative level over the years. The correction also remained stable for the most part, although some loss was seen over a 9-year span. "This is normal because they have very high myopia, and we expect to see some evolution of the myopia in these young patients over the years," Dr. Zaldivar said. Most of the 31 patients gained BSCVA and maintained that gain over the follow-up period. A few, however, including two patients with cataracts, lost some lines. Aside from the development of cataracts in two patients, few complications were seen. Glaucoma did not develop in any patients, and the ICL material was well-tolerated over the follow-up period. Complications David D. Dulaney, MD, in private practice at the Barnet Dulaney Perkins Eye Center in Phoenix, also described his experiences with the ICL, noting that this is the only phakic IOL that he has used. Complication rates are similar between ICL implantation and laser vision correction procedures, he said. "ICL complications are almost always straightforward and easy to treat by an experienced anterior segment surgeon," Dr. Dulaney said. "Secondly, if one considers laser vision correction complications related to corneal infections, prolonged steroid use, and penetrating keratoplasty, the risk of serious intraocular complications may be comparable to that of the ICL." A series of complications is possible with either LASIK or PRK, he added. With the ICL, complications that occurred in the FDA myopia study included removal and replacements for sizing or power, re-positions, rotations (in the toric study), repetition or enlargement of iridectomies, cataract removal, two macular hemorrhages (1 week and 3 months following implantation), and three retinal detachments (one about 6 months postoperatively and the other s after 2 years). The degree of myopia in the patients with detachment was 9, 16, and 17 D, and the incidence was comparable to what it would be without surgery. "ICL complications are easy to treat, with a return to good vision very quickly, usually within hours to days," Dr. Dulaney told attendees. "I know that all of you who've done LASIK or PRK have things that are very difficult to get rid of at least I certainly do. They're not easy to treat, they're prolonged, and they often don't have an easy surgical or medication solution. But treating the ICL complications requires very little knowledge or skill that the anterior segment surgeon doesn't already have." Dr. Dulaney then compared reports of complications: In a review of 1,870 English-language articles and 16 original studies from 1963 to 2003, data pooled from more than 90,000 penetrating keratoplasties showed that the incidence of endophthalmitis had declined over the 40-year period but from 2000 to 2003 was still two per 1,000. In personal communications, two surgeons who have completed thousands of ICL procedures reported no cases of endophthalmitis. In addition, a report on ASCRS 2004 survey results from 46 surgeons who had performed more than 100,000 LASIK procedures indicated that one infection occurred in about every 2,000 procedures, and 6.2% of these eyes required penetrating keratoplasty.

5 Page 5 of 5 Eric D. Donnenfeld, MD, has reported that infection is much more common following PRK than LASIK. "Many surgeons as well as other doctors tend to think an ICL is just an intraocular procedure with a bad connotation, and laser vision correction is just treating the cornea. A perspective I'd like to leave you with is that if you follow all laser vision correction cases, including PRK and LASIK, to their final outcome, the risk of serious intraocular complications, both very low, may not be all that different," Dr. Dulaney said. "I believe that as more data are accumulated, we'll actually find that the incidence of these vision-threatening intraocular problems is less with an ICL than following laser vision correction," he added.