Eyeworld

EW FEATURE 42 by Maxine Lipner Senior EyeWorld Contributing Editor The pioneer spirit: Unmapped presbyopia correction territories I n addition to more traditional approaches to correcting pres- byopia, such as lens- or corneal-based technology, an innovative frontier is emerg- ing. Inroads are being made in everything from femtosecond lens softening to enhancement of scleral plasticity. EyeWorld took a closer look at some of these to see how they might eventually civilize pres- byopic territory. Smithing away at lens softening One innovative new approach is using the LensAR femtosecond laser (Winter Park, Fla.) to soften the lens nucleus. The concept here is to place femtosecond pulses in the nucleus, according to Ronald R. Krueger, M.D., medical director of refractive surgery, Cole Eye Institute, Cleve- land, and professor of ophthalmol- ogy, Cleveland Clinic. "The lens nucleus is then softened as com- pared to the harder nuclear state that might have been there before, and that would allow for more flexi- bility of the crystalline lens," Dr. Krueger said. With the technique, the laser will focus very localized pulses along any specific geographic pattern in whatever volume needed. "We don't have to cut through the anterior part of the lens to get in the middle of it—the laser goes right to the mid- dle," Dr. Krueger said. "We can put pulses in any number of different patterns in order to try and make the lens softer so that it's more flexi- ble." Results so far, however, have been modest and somewhat unpre- dictable. "We've shown that we could make the lens more flexible experimentally, but in treating pa- tients we have not seen any consis- tent return of that accommodative mechanism," Dr. Krueger said. "What we have seen is that we can put the laser pulses inside the lens without having a cataract form from them." There have been a few cases where the technique has shown promise. "We have seen a few cases February 2011 PRESBYOPIA June 2011 • AT A GLANCE • Lens softening with the femtosec- ond laser hopes to restore flexibility to the crystalline lens • Liquid crystal eyeglasses change power at the press of a button • Scleral expansion bands purport to help the posterior zonules work in changing lens shape • LaserACE restores the plasticity of the sclera, increasing the efficiency of the ciliary body continued on page 44 Intracorneal continued from page 63 "The materials that have been developed and are used by all the in- lays—even if they are different materials—are very friendly to the cornea," he said. With 4 years of fol- low-up on the Flexivue, "using confocal microscopy we have demonstrated that even after years there are not any inlay-associated degenerative issues to the cornea." However, as recently as 2009, there was a report of one patient who developed late-onset ulceration after implantation of the Revision Optics' device for the treatment of hyperopia, which "most likely repre- sents a neurotrophic melt," the au- thors wrote. 1 Another complication was reported in 2004, epithelial peri- lenticular opacity, and again, the subjects had undergone intracorneal inlay implantation for the correction of hyperopia. 2 Dr. Thompson said all corneal inlays have the potential for compli- cations, with a similar incidence of LASIK-type complications, including thin flaps, epithelial ingrowth, striae, and surgical corneal abrasion. Conversely, studies to date have shown the inlays "typically blur dis- tance less than monovision," he said. "The corneal correction of pres- byopia is an exercise in compromise. The question the patient has to ad- dress is what he/she is willing to give up at distance to help with near vision." What the future holds Dr. Pallikaris said researchers learned from those earlier mistakes, and "presbyopia treatment selection is closely related to patient selection," he said. "That means one of the most important steps of the surgery is to understand the necessities of your patient for near vision." He added this should include which eye to operate on, what type of surgery the eye should receive, what mate- rial will be placed in the eye, "and even the possibility of avoiding sur- gery." Dr. Grabner prefers to use the inlays on hyperopes (up to 1.5 D) without spectacle correction; a new diagnostic tool (AcuTarget, AcuFocus) has significantly im- proved centration capabilities. "Emmetropic presbyopes are the most difficult patients to please," Dr. Waltz said. "In my opinion, the only other treatment that can compete with the inlay is monovision." Dr. Thompson said for ametropic pres- byopes, he would combine the inlay with LASIK. He added, "in the 88 pa- tients I treated in the clinical trial I removed three. That is a great track record compared to the amount of monovision LASIK patients that come back to me and want the near eye brought closer to distance. I be- lieve corneal inlay technology will play a large role in lessening pa- tients' dependence on reading glasses until they have cataract sur- gery with a premium implant to help their near." As long as there is no definitive surgical preference for the treatment of presbyopia, corneal inlays will continue to be investigated and used, according to the experts. "I believe in this technique even though some surgeons are skeptical; I believe it has a great future," Dr. Pallikaris said, adding, "someone must believe" and buck the system for true innovation and science to progress. EW References 1. Verity SM, McCulley JP, Bowman RW, Cavanaugh HD, Petroll WM. Outcomes of PermaVision intracorneal implants for the cor- rection of presbyopia. Am J Ophthalmol. 2009;147:973-7 Epub 2009 Mar 9. 2. Alio JL, Mulet ME, Zapata LF, Vidal MT, de Rojas V, Javaloy J. Intracornal inlay compli- cated by intrastromal epithelial opacification. Arch Ophthalmol. 2004;122:1441-6. Editors' note: Dr. Grabner has no finan- cial interests related to his comments, but has received travel support in the past. Drs. Thompson and Waltz have financial interests with AcuFocus. Dr. Pallikaris has a financial interest with Presbia. Contact information Grabner: +011 43 662-4482-3701, g.grabner@salk.at Pallikaris: pallikar@med.uoc.gr Thompson: 605-328-3937, vance.thompson@sanfordhealth.org One approach to correcting presbyopia involves lens softening with the femtosecond laser. Pictured here: Femtosecond laser pulses in a living human lens, creating bubbles immediately after placement in a waffle pattern Source: Ronald R. Krueger, M.D.

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