Long-term evaluation of complications and results of photorefractive keratectomy in myopia: an 8-year follow-up.

PURPOSE

To evaluate 8-year results of photorefractive keratectomy (PRK) for myopia in terms of safety, efficacy, stability, and late complications.

METHODS

From 371 myopic eyes of 203 patients who underwent PRK using NIDEK EC-5000 excimer laser with 5.5- to 6-mm ablation zones in Basir Eye Center, Tehran, Iran, during 1997-1998, data of 179 myopic eyes of 98 patients, who participated in annual examinations, were analyzed. Treated eyes were divided into 3 groups according to preoperative refraction: low myopia [<or=-6.00 diopters (D)], moderate myopia (-6.10 to -10.00 D), and high myopia (>-10.00 D). The main outcome measures were safety, efficacy, stability, and postoperative complications.

RESULTS

Eight years after PRK, 69.64%, 44.44%, and 45.65% of the low, moderate, and high myopic groups were within +/-0.5 D of emmetropia. Sixteen eyes (4.31% of original cases) underwent retreatment mainly because of regression. Although a small myopic shift occurred up to 8 years after surgery, changes in myopic regression stabilized in all myopic groups within 24 months. Four eyes (2.06%) lost 2 lines of best spectacle-corrected visual acuity (1 eye for corneal haze and other 3 for problems not related to refractive surgery). Corneal haze occurred in 11.34% especially in medium and high myopic groups, but it cleared within 2 years in 68.2% of cases.

CONCLUSIONS

Based on our study, PRK seems to be a safe, efficient, and stable surgical procedure, and if patients obtain a good result with the initial treatment, then their results are relatively stable over time.