Femtosecond LASIK Retreatments After Primary Myopic Photorefractive Keratectomy

The purpose of the study was to evaluate the results and complications of laser-assisted in situ keratomileusis (LASIK) using a femtosecond laser as a retreatment modality of myopia and myopic astigmatism after previous myopic photorefractive keratectomy (PRK).

In this retrospective, consecutive, noncomparative case series study, 69 eyes of 41 patients receiving femtosecond LASIK after previous myopic PRK were evaluated. The mean age was 43.0 ± 8.9 years. The preoperative mean SE was -1.82 ± 1.01 diopter (D), range -0.62 to -6.25. The mean central epithelial thickness was 65 ± 5 μm. A flap was created using a low-energy femtosecond laser (Ziemer LDV Z8), with a programmed thickness calculated by adding 40 μm to the epithelial thickness. Refractive ablation was performed using a Technolas Teneo 317 laser (Bausch and Lomb).

Twelve months after LASIK, the mean SE was -0.03 ± 0.17 D, with all eyes ≤0.50 D of SE. The mean DE was 0.30 ± 0.25, with 62 eyes (89.9%) ≤0.50 D and all eyes ≤1 D. The mean corrected distance visual acuity (CDVA) was 0.04 ± 0.10 logMAR; no eye lost more than 1 line of CDVA. The mean uncorrected distance visual acuity was 0.07 ± 0.13 logMAR, being 20/25 or better in all eyes. The safety index (postoperative CDVA/preoperative CDVA) was 1.05. The efficacy index (postoperative uncorrected distance visual acuity/preoperative CDVA) was 0.98. No significant complications occurred.

Myopic retreatments by femtosecond LASIK after primary PRK yielded excellent refractive results without relevant complications. The flap thickness must be tailored to the epithelial thickening after PRK.