Making Laser Surgery Safer for RK Patients

Newswise — A new study being presented at the American Academy of Ophthalmology's 2007 Annual Meeting suggests that the laser surgery can help improve and possibly stabilize the vision of patients who have radial keratomy (RK) while preventing previously common side effects from the surgery.

In the study, 22 patients who had previously undergone RK and subsequently developed unanticipated changes in prescriptions for correcting vision underwent advanced surface ablation with miomycin C, an anti-scarring medication. Most patients experienced a significant improvement in corrected and uncorrected vision without any complications.

"This gives new hope to patients who have had RK and have developed problems ," said Navaneet Borisuth, MD, Ph.D, the presenting author of the poster. "Most refractive surgeons would shy away from these patients because we were not able to deliver the results that they expected. Now, with this refinement, we can deliver a very good quality of vision for our RK patients."

Before the advent of laser surgery, RK was the predominant method of surgically correcting nearsightedness in patients. The procedure involved a surgeon making small incisions in the cornea, thus relaxing it and flattening it, which in turn corrected myopia. However, some patients developed farsightedness, or hyperopia, as scarring around the incisions caused the cornea to tighten and further change its shape. Efforts to correct this problem with laser technologies, such as photorefractive keratectomy (PRK) or LASIK, were fraught with complications and were often unsuccessful.

"The problem with PRK was patients would develop haze, which is a type of scarring response on the cornea and which could result in worse vision than the vision that the patient started out with," said Dr. Borisuth.

Dr. Borisuth and co-author Prem Virdi, MD, treated 16 patients with LASEK and 6 with EpiLASIK for refractive error. The patients had had as many as 16 incisions made on the cornea with RK. After the most recent treatment, the doctors applied mitomycin C for 12 seconds and then assessed the results.

"Basically, all the patients had a significant improvement in uncorrected vision, and in terms of corrected vision, 95.5 percent of the patients were within one diopter of what we were aiming for," Dr. Borisuth said. "No patient had vision worse than 20/25." One patient did experience haze as a complication from EpiLASIK.

Further long-term studies are necessary to confirm the benefits of the approach. Nonetheless, the study suggests that RK patients may have surgical options that they previously did not. "These refinements do represent a safe way of treating refractive error in patients after RK," Dr. Borisuth said.

About the American Academy of Ophthalmology The American Academy of Ophthalmology is the world's largest association of eye physicians and surgeons—Eye M.D.s—with more than 27,000 members worldwide. Eye health care is provided by the three "O's" " opticians, optometrists and ophthalmologists. It is the ophthalmologist, or Eye M.D., who can treat it all: eye diseases and injuries, and perform eye surgery. To find an Eye M.D. in your area, visit the Academy's Web site atwww.aao.org.