January 12, 2004.
Courtesy of American Academy of Ophthalmology.
ANAHEIM, CALIF. -- Leading cataract and refractive surgeons discussed the merging of cataract and refractive surgeries through use of intraocular lenses (IOLs) at the Annual Meeting of the American Academy of Ophthalmology, the Eye M.D. Association.
In his opening remarks, moderator Walter Stark, MD, professor of ophthalmology at Johns Hopkins Hospital, said that because cataracts are the major cause of blindness worldwide, he expects there will be more lens exchanges.
Morcher Implant Devices.
Samuel Masket, MD, clinical professor of ophthalmology, UCLA Jules Stein Eye Institute, said, "Morcher implant devices, aniridic rings that allow surgeons to reduce the size of the patient's pupil for eyes with iris defects, are crucial in reducing glare." Although an FDA compassionate device exemption is necessary in the United States, Masket is hopeful these viable and valuable devices will become more widely available for patients who have defective irises from birth defects or trauma.
Super Vision with Refractive Clear Lensectomy.
Jack T. Holladay, MD, clinical professor of ophthalmology, Baylor College of Medicine, emphasized the importance of assessing contrast sensitivity and spherical aberrations and explained the use of the Tecnis Z 9000 IOL, which allows light to focus perfectly on the retina, thus restoring contrast sensitivity and nighttime vision.
Implantable Miniature Telescope.
Douglas Koch, MD, professor and chair of ophthalmology, Baylor College of Medicine, said, "The IMT provides a 60 percent field of vision as opposed to only 20 percent with an external telescope for patients who have lost vision from macular degeneration." The IMT is currently in Phase I clinical trials. So far, 77 percent of patients achieved an improvement in central vision of two eye-chart lines, and 62 percent achieved an improvement of three lines.
Multifocal IOLs for Presbyopia.
"Unlike glasses or contact lenses, the multifocal IOL provides two focal ranges at the same time," said Roger Steinert, MD, associate professor of ophthalmology, Harvard Medical School. "The downside is that contrast sensitivity is somewhat compromised." In studies of the AMO Array multifocal lens, patients attained near visual acuity of 20/40, increased depth of focus, and 81 percent reduced their dependence on glasses. "The advantage of the multifocal lens," he said, "Is that it should work for everyone, whereas only two-thirds of patients are able to adjust to monovision, in which one eye is corrected for near vision and the other for distance."
Accommodating IOLs for Cataract Surgery and Refractive Lensectomy.
Richard L. Lindstrom, MD, adjunct professor emeritus, University of Minnesota, discussed Eyeonics' CrystaLens, which was just approved by the FDA last Friday. Clinical trials found that 98.4 percent of patients achieved 20/40 or better visual acuity. "The important thing about this type of lens is that it restores the full range of vision, but my main concern is that this is the first truly effective technology that won't be covered by Medicare. It will not be available to those who need it most -- low-income elderly patients."
Refractive Lens Exchange.
I. Howard Fine, MD, clinical professor of ophthalmology, Casey Eye Institute, Oregon Health and Science University said refractive lens exchange with IOLs will be the dominant refractive procedure because it's a "win-win-win" solution "It addresses all components of patients' refractive errors, including presbyopia." Dr. Fine said. "It reduces the number of patient problems for surgeons, and it even benefits the government because there will be "a dramatic decrease in the expense of cataract surgery."
Copyright © 2004 , World Publishing Co. All rights reserved.
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