A new predictor of refractive and optical results after photorefractive keratectomy (PRK)

Purpose. To assess a new method for predicting refractive outcome and comeal optical clarity after PRK. Methods. Digitalized retroillumination images (DRI) of the cornea, taken immediately after PRK, were analyzed with respect to smoothness of surface and optical homogeneity. Forty eyes, corrected for myopia ranging from -1.75D to -21.00D were studied. Minimum follow-up was 12 months. Results. The 9 eyes which showed the most perfect DRI (preoperative refraction -1.75D to -13.75D) had the best refractive outcome (78% within 1 .ODD of aim) and the least haze (89%s0.5+). The 15 eyes which exhibited the worst DRI (preoperative refraction -2.75D to -21.000) had the poorest refractive results (60% within 1.00D and 33% within 3.00D to 4.00D of aim) and the most haze (67% with 1 to 2+). Conclusions. DRI appears to be useful predictor of refractive outcome and comeal clarity after PRK. The results further support the importance of creating an optimally smooth comeal surface when performing PRK.