A Method for Examining Surface and Interface Irregularities after Photorefractive Keratectomy and Laser in situ Keratomileusis: Predictor of Optical and Functional Outcomes

PURPOSE: To develop a system for the examination of the ablated surface after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and to correlate the surface regularity to the functional outcome. METHODS: A Nidek Eas-1000 Anterior Eye Segment Analysis System was used to examine the ablated surface or the interface regularity immediately after PRK and LASIK. Eighty eyes were evaluated and divided into three study groups; group 1; regularity (18 eyes), group 2; mild irregularity (32 eyes) group 3; severe irregularity (30 eyes). RESULTS: At 12 months postoperatively, group 1 (regularity) showed the best percentage of eyes with 0 haze (100%) and with a refraction +/- 1.00 D of plano (89%); group 2 (mild irregularity) 84% had 0 haze and 62% were +/- 1.00 D of plano; group 3 (severe irregularity) 27% had 0 haze and 47% were +/- 1.00 D of plano. CONCLUSION: The patients with no postoperative irregularity had a sharply lower incidence of haze and a better refractive outcome with respect to plano, confirming the influence of ablation regularity on the results and the importance of this analysis in clinical practice.