EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/307638
EW FEATURE 63 Lens- and cornea-based treatments in the pipeline may make that decision easier to address for refractive surgeons F ew refractive surgeons would disagree that the most difficult patient to ed- ucate and treat today is the near-emmetropic presby- ope. These patients have rarely gone to an eyecare professional and may not completely comprehend why their vision is not as crisp as it once was. In short, they are a highly frus- trated group of people, and today's technologies cannot fully restore their accommodative vision. The loss of contrast sensitivity for only a partial gain of accommodation is not ideal, most surgeons agree. EyeWorld asked several leading surgeons how—or if—they would treat this particularly finicky patient group and what future technologies under investigation might alter their opinions. "Have we reached a point in our intraocular lens technology that would justify and legitimize an em- metropic, presbyopic lens exchange? No," said Louis "Skip" Nichamin, M.D., private practice, Laurel Eye Clinic, Brookville, Pa., adding he "can count on one hand" the num- ber of near emmetropes he has im- planted. "I believe in my heart of hearts that will change down the road," he said. Stephen S. Lane, M.D., medical director, Associated Eye Care, Stillwa- ter, Minn., and adjunct clinical pro- fessor, University of Minnesota, Minneapolis, said while he offers re- fractive lens exchange to his presby- opic population, "I do it infrequently because I'm not a real enthusiast of the current technologies." Hitting both distance vision and near vision targets to give the patient what he/she wants "is a very tall order," he said. "Unless and until we get to a place where we have basically a risk- free procedure with a near perfect or February 2011 October 2011 Challenging refractive cases by Michelle Dalton EyeWorld Contributing Editor Presbyopia: How to treat the near emmetrope not only corneal astigmatism but also lenticular astigmatism, he said. "If some of the astigmatism is coming from the lens, you need to take that into account because that's going to go away when you remove the cataract. You want to make sure you're calculating the toric lens Astigmatism continued from page 62 continued on page 64 Red reflex view of a Synchrony dual-optic lens after 1 year post-op Source: Victor Bohórquez, M.D. AT A GLANCE • Near-emmetropic presbyopes re- main one of ophthalmology's great- est challenges; finding an optimal treatment would be "the holy grail" • Current technology does not pro- vide enough accommodative effect for this patient group • Newer lens-based and cornea- based procedures have great po- tential, but only if they can offer more than 5-6 D of accommodation power on just the corneal astigma- tism," he explained. Similar to PCRIs, the complica- tion with toric lenses is putting them in the wrong axis, Dr. Mamalis said. It's critical that the toric lens be properly aligned with the axis of the astigmatism. Just like with PCRIs, Dr. Mamalis said he takes the toric IOL calculations with him to the operat- ing room and tapes them above the microscope in the proper orientation to double check the alignment. EW Editors' note: Dr. Devgan has financial interests with Abbott Medical Optics (AMO, Santa Ana, Calif.), Alcon (Fort Worth, Texas), Bausch & Lomb (Rochester, N.Y.), Haag-Streit (Mason, Ohio), and Hoya (Santa Clara, Calif.). Dr. Mamalis has financial interests with AMO, Alcon, and Allergan (Irvine, Calif.). Contact information Devgan: 800-337-1969, devgan@gmail.com Mamalis: 801-581-6586, nick.mamalis@hsc.utah.edu consistent astigmatism, Dr. Devgan said. "Patients with irregular or asym- metric astigmatism will not do as well with toric IOLs. You can make asymmetric incisions with PCRIs, but toric IOLs are symmetric," he said. As with PCRIs, Dr. Mamalis said surgeons might want to think twice about implanting toric IOLs in patients with corneal ectatic dis- eases. In patients with a higher de- gree of astigmatism, when performing corneal topography, it is important to find out if there's "Toric lenses are great for patients with regular, symmetric, and con- sistent astigmatism," Dr. Devgan said. There are few risks in performing PCRIs, according to Dr. Mamalis Source: Uday Devgan, M.D., F.A.C.S. 52-67 Feature_EW October 2011-DL33_Layout 1 9/29/11 4:52 PM Page 63