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Chicago-A lack of evidence demonstrating reversibility of cornea-based laser procedures for presbyopia is an issue of concern for the use of these techniques, said Michael C. Knorz, MD, at Refractive Surgery 2012.
“While excimer laser ablations from various manufacturers (PresbyLASIK, Abbott Medical Optics; PresbyMax, Schwind eye-tech solutions; Supracor, Technolas Perfect Vision) and femtosecond laser intrastromal ablation (Intracor, Technolas Perfect Vision) are effective treatments in the majority of patients, visual side effects and reduced vision can occur and may be intolerable for some patients,” said Dr. Knorz, professor of ophthalmology, Medical Faculty Mannheim, University of Heidelberg, Germany. “Reversibility of these procedures has not been shown to date. Therefore, surgeons must take utmost care in patient selection to make sure that the procedure does not cause permanent harm.”
Reviewing outcomes of the cornea-based laser procedures, Dr. Knorz cited two publications. One paper by Alio et al. reporting on excimer laser correction of presbyopia in 50 eyes of 25 patients showed 20% lost 2 lines of distance corrected visual acuity (VA) and 50% lost 2 lines of near corrected VA. In a paper by Dr. Knorz and colleagues reporting on 63 patients who underwent the intrastromal femtosecond laser procedure in the nondominant eye, 7% of eyes lost 2 lines of distance corrected VA and 11.5% lost 2 lines of corrected near VA. Almost 20% of patients were not satisfied with the result, and 12% said they would not have the surgery again.
“For these patients we have to consider whether it is possible to reverse the surgery to make them happy again. In a Medline search conducted on 11/5/12, there were no papers on reversibility of corneal presbyopia laser surgery performed with either PRK, LASIK, or IntraCor,” Dr. Knorz said.
He also discussed his own experience with a 65-year-old woman who had the femtosecond laser procedure in her right eye. She was very unhappy with the result, and after waiting 1 year, wavefront-guided PRK was performed without benefit. Another wavefront-guided PRK procedure was done 6 months later, but was also unsuccessful in reversing the cornea aberrations that were induced by the presbyopic procedure.
None of the procedures Dr. Knorz discussed are FDA-approved. He has no relevant financial interests to disclose.
First patient dosed at the Tokyo Medical Center by Belite Bio in Phase 2/3 DRAGON II clinical trial