Photorefractive keratectomy after radial keratotomy

BACKGROUND: Twenty-three eyes of 22 patients remained undercorrected 5 to 49 months after radial keratotomy, either alone or in combination with transverse keratotomy. METHOD: We attempted to correct the residual myopia ranging from -1.25 to -5.75 diopters (D) (with astigmatism of 0 to 1.25 D) with photorefractive keratectomy. The mean age of patients was 26 years (range 22 to 40 years). RESULTS: After photorefractive keratectomy (follow-up 6 to 17 months) uncorrected visual acuity was equal to or better than 20/20 in 39% (9 eyes), better than 20/25 in 65% (15 eyes), and better than 20/40 in 74% (17 eyes). Spectacle-corrected visual acuity was equal or better than 20/40 in all eyes; one eye (4%) lost two lines of spectacle-corrected visual acuity. Refractive error was within +/-0.50 D in 48% (11 eyes) and within +/-1.00 D in 65% (15 eyes). Undercorrections of more than 1.00 D occurred in 22% (5 eyes) and overcorrections of more than 1.00 D occurred in 13% (3 eyes). No or minimal haze was present in 57% (13 eyes), mild haze in 39% (9 eyes) and moderate haze in 4% (1 eye). Final uncorrected visual acuity was better (p=0.0002) and haze was less (p=0.003) in the group with less than -3.00 D than in the group with greater than or equal to -3.00 D. CONCLUSION: Photorefractive keratectomy after radial keratotomy is safe but less effective and less predictable in eyes with greater than or equal to -3.00 D compared to those with less than -3.00 D.