Results of photorefractive keratectomy in keratoconus suspects at 4 years

PURPOSE: We studied the long-term results of photorefractive keratectomy (P RK) in keratoconus suspects detected by videokeratography (TMS). METHODS: Bilateral inferior corneal steepening was detected in 6 candidates for PRK presenting with moderate myopia or astigmatism. Mean follow-up was 44.5 +/- 4.4 months (range, 38 to 54 mo). Mean spherical equivalent refrac tion was -5.18 +/- 1.60 D (mean sphere, -4.73 D; mean cyclinder, -0.92 D) w hich was stable for at least the preceding year. The quantitative measureme nt of inferior corneal steepening (I-S value) was greater than +1.60 (mean, 1.83 +/- 0.11) in all eyes. An Aesculap Meditec Mel 60 excimer laser was u sed for the PRK procedures and mean follow-up was 44.5 months. Postoperativ e pachymetric measurements were also performed in 6 eyes. RESULTS: Postoperative uncorrected visual acuity was 20/20 in 8 eyes (66.6% ) and 20/32 or better in all eyes with a mean postoperative spherical equiv alent refraction of -0.70 +/- 0.74 D (mean sphere, -0.63 D; mean cyclinder, -0.39 D). Five eyes (41.6%) were within +/- 0.50 D spherical equivalent re fraction. Inferior steepening was associated with thinning of the inferior cornea which was statistically significantly thinner than the superior thic kness (Student's t-test, P < .05). There were no wound healing problems or any sign that the excimer laser adversely affected the cornea during follow -up. CONCLUSIONS: Photorefractive keratectomy seems to be a safe procedure for r educing or eliminating myopia or astigmatism in keratoconus suspect eyes-mo st probably forme fruste keratoconus-with a stable refraction, but this may be different in eyes with early keratoconus, known to be a progressive dis ease.