Trial aims to define relative pros, cons of LASIK and PRK with mitomycin-C

Initial results from a prospective, randomized clinical trial show that both LASIK and PRK with adjunctive topical mitomycin-C (MMC) are safe and effective for decreasing myopia and astigmatism after penetrating keratoplasty (PKP) for keratoconus, but suggest a possible advantage of the surface ablation technique for better reduction of cylinder, reported Reneé Solomon, MD.

The study enrolled patients who had their sutures removed for a minimum of 3 months and had an SE in the range of -2 to -10 D. All treatments were performed by Eric D. Donnenfeld, MD, with a goal to achieve a plano postoperative refractive result. Both Dr. Solomon and Dr. Donnenfeld are in private practice in Ophthalmic Consultants of Long Island, New York.

Dr. Solomon reported 6-month outcome data for 20 patients who had undergone PRK with MMC 0.02% and 17 patients treated with conventional LASIK. Preoperatively, mean sphere was -4.11 D in the PRK group and -3.87 D in the LASIK group, and mean cylinder values were -4.33 D for the PRK group and -3.92 in the LASIK group. The postoperative results showed mean sphere and cylinder values were -0.62 D and -1.28 D, respectively, in the PRK group and -0.75 D
and -2.11 D, respectively, in the LASIK group. There have been no problems with haze in the PRK group, she said.

"Visual rehabilitation after an anatomically successful corneal transplant can be challenging due to anisometropia and astigmatism," she said. "In patients who are intolerant to gas permeable contact lens wear, both PRK with adjunctive topical MMC and LASIK have been shown effective in treating residual refractive error.

"However, there have been no controlled prospective clinical trials comparing the two procedures," Dr. Solomon said. "This study is now being expanded to include additional study sites, and long-term follow-up will be necessary to evaluate potential advantages of one procedure over the other."

The study was supported by a research grant from the American Society of Cataract and Refractive Surgery Foundation.