Long-Term Outcome of Epi-LASIK for High Myopia

Abstract

Purpose

To evaluate the long-term outcomes of epipolis laser-assisted in situ keratomileusis (epi-LASIK) for high myopia.

Methods

High myopic patients who underwent epi-LASIK during 2004 and 2005 were included in this study. Epi-LASIK was performed with an automatically rotational epikeratome (KM-5000D). Postoperative visual acuity, manifest refraction, and haze formation were assessed 3 mo, 6 mo, 1 y, and 3 y after surgery. Results were compared by dividing patients into 2 groups according to preoperative mean refractive spherical equivalent (MRSE): group A (≥–6 D to −10 D; group B ≥–10 D). The differences within groups were analyzed using mixed model for continuous variables. The differences between groups were analyzed using t test or rank sum test for continuous variables, and Pearson χ² or Fisher exact probabilities for categorical variables.

Results

A total of 20 patients (33 eyes) were followed up for more than 3 years with 17 eyes in group A (MRSE −8.15±1.41 D) and 16 eyes in group B (MRSE −12.95±2.91 D). While postoperative refraction regression occurred in both groups, it was more prominent in group B (p<0.05). The long-term predictability is good in group A with 14 eyes (82.35%) within ±1 D of attempted correction at 3 years while the percentage in group B was 18.75%. The efficacy index was significantly different between the 2 groups (p<0.05): 0.84±0.29 for group A and 0.61±0.47 for group B at 3 years. The safety index was above 1.0 at each timepoint in both groups. Haze was at low level and faded with time after epi-LASIK.

Conclusions

Epi-LASIK had a satisfactory long-term effect for high myopia of less than −10 D. Myopic regression limited the satisfaction of epi-LASIK in eyes with myopia of more than −10.0 D.