Photorefractive keratectomy with mitomycin-C after corneal transplantation for keratoconus

Abstract

To evaluate the efficacy of photorefractive keratectomy (PRK) for residual refractive error after penetrating keratoplasty (PKP) for keratoconus. Private ophthalmic clinic. Case series. Consecutive patients who had PRK augmented with topical mitomycin-C (MMC) after PKP for keratoconus were retrospectively reviewed. Patients were divided into a a low cylinder group (refractive cylinder ≤ 6.00 D) and a high cylinder group (refractive cylinder >6.00 D). Visual acuity, refraction, and keratometry were analyzed preoperatively and 1, 3, 6, and 12 months postoperatively. The study comprised 47 eyes (41 patients). The spherical equivalent (SE) decreased from -4.24 D ± 3.23 (SD) preoperatively to -0.71 ± 1.03 D 12 months postoperatively in the low cylinder group and from -4.19 ± 3.54 D to -2.45 ± 3.42 D, respectively, in the high cylinder group. The refractive cylinder decreased from -4.27 ± 1.4 D to -1.71 ± 1.55 D, respectively, in the low cylinder group and from -7.78 ± 1.21 D to -4.6 ± 2.54 D, respectively, in the high cylinder group. By the last follow-up, 8.3% of patients had lost 2 lines of corrected distance visual acuity. There were no cases of corneal haze greater than 2+ or of graft rejection. Penetrating keratoplasty with adjunctive MMC decreased several refractive variables in patients with previous PKP. These results compare well with those in the published literature and suggest PRK is as effective as, and probably safer than, laser in situ keratomileusis in treating refractive error in these cases. No author has financial or proprietary interests in any material or method mentioned.