EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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For some surgeons, these lenses offer hope to high myopes. For others, the potential complications outweigh the potential benefits Editors' note: This column discusses technologies that are not commercially available in the U.S. T he correction of high my- opia is limited, but phakic IOLs do provide a surgical option. "For many years we have been looking for a quality anterior chamber phakic IOL that could be easily performed in a clean room rather than an operating room," said Eric D. Donnenfeld, MD, partner at Ophthalmic Consultants of Long Island, Rockville Centre, N.Y., and clinical professor of ophthalmology, New York University Medical School. With only two phakic lenses available in the U.S.—the Verisyse (Abbott Medical Optics, Santa Ana, Calif.) and the Visian (STAAR Surgi- cal, Monrovia, Calif.)—options for U.S. physicians will remain limited. A third lens, the Cachet (Alcon, Fort Worth, Texas), remains in clinical studies, as does a foldable version of the Verisyse (Veriflex, Abbott Medical Optics); the Visian ICL with CentraFlow (STAAR Surgical) is not available in the U.S. Neither the Verisyse nor the ICL is a perfect solution, said Kerry K. Assil, MD, medical director and chief executive officer, Assil Eye Institute, Beverly Hills and Santa Monica, Calif. "People have looked for a better mousetrap but haven't been able to come up with one yet," he said. Al- ternative attempts have focused on developing angle-fixated, anterior chamber IOLs, which have generally failed, as these lenses sit too close to the peripheral endothelium and also caused "unacceptable iris root in- flammation. That chronic low grade trauma may eventually lead to the ovalization of the pupil," among other issues, Dr. Assil said. Richard L. Lindstrom, MD, founder, Minnesota Eye Consult- ants, Minneapolis, said those kinds of complications are why he stopped implanting phakic lenses 2 years ago. "I was quite excited about the Alcon Cachet, but it is now showing select cases of late PAS, pupil oval- ing, and unpredictable endothelial cell loss. I am also seeing late cases of cataract, pigment dispersion, secondary glaucoma, and unex- pected endothelial cell loss with the Visian," he said. His best long-term results have been with the Verisyse, "but I have seen erosion through the iris and subluxations here in select cases as well, and patients often are unaware of their problem." As most surgeons can confirm, phakic IOL patients are also more likely to develop cataract/dysfunc- tional lens syndrome in their 50s. Additionally, the majority "has sig- nificant astigmatism. And they're young, so you shouldn't preform relaxing incisions," said Jeffrey D. Horn, MD, in private practice, Vision for Life, Nashville, Tenn. "Ideally, we'd like to go in with a lens that could correct the refraction and astigmatism in one fell swoop." While the field has been stag- nant for a while, the FDA recently approved the Visian toric, "which should be a significant addition to our armamentarium," Dr. Donnenfeld said. Below, an update on current phakic IOLs. Cachet Dr. Horn, a principal investigator for the Cachet since its phase 2 studies, said that in his hands, complications have been few. He's implanted 53 patients. "I did have to reposition the lens in a couple of patients, but that's not unique," he said. Some patients do experience a greater cell loss than anticipated, however. "It's why I think the lens is on the back burner," he said, although there is an active 10-year study. In the one patient with a "cell count that was lower and dropping faster than we would like," Dr. Horn said he ex- planted the Cachet. "The lens was vaulting closer to the corneal endothelium than almost all of the other patients that I had." Yet these patients remain some of his happiest, he said. The Cachet "has been shown to be better than previous generation anterior chamber phakic IOLs; it is demonstrating the same complica- tions of previous generation lenses but with a reduced incidence," Dr. Donnenfeld said. During the implantation phase of the studies, Dr. Horn noted that the lens did have some rotation that did not alter visual outcomes, but would make it an unlikely platform for a toric version, should the lens be submitted for U.S. regulatory approval. Verisyse/Artisan In addition to serving high myopes, in the "right type of keratoconic patient," the Verisyse lens "does extremely well over time," Dr. Assil said. "These lenses have helped to avoid the alternative option of corneal transplantation on multiple occasions. Outside the U.S., this is the most popular lens in the world as a secondary IOL (in remedying aphakia)." There are two versions of the Verisyse, one of which is foldable, Dr. Assil said. The foldable version is not available in the U.S. "What I like about this lens is that it doesn't cause cataracts be- cause it sits in the anterior chamber and also relatively far from the en- dothelium," he said. "In a very tiny subset, it can create endothelial cell loss over time, necessitating explantation (in less than 1% of implanted patients)." That subset includes those with shallow chambers or vigorous eye rubbers— EW REFRACTIVE SURGERY 49 June 2014 by Michelle Dalton EyeWorld Contributing Writer Phakic IOLs: Not perfect, but viable options An eye with a Verisyse phakic IOL and a nuclear cataract Source: Kevin Miller, MD The Visian ICL Source: STAAR Surgical Device focus continued on page 50 48-50 Refractive_EW June-DL_Layout 1 6/3/14 12:36 PM Page 49