Clinical observation of laser subepithelial keratomileusis for high and super-high myopia

Objective To investigate the long-term therapeutic effects and factors that determine the effectiveness of laser subepithelial keratomileusis (LASEK) in the correction of high and severe myopia. Methods LASEK was performed on 202 eyes of 105 patients with myopia. The eyes were divided into a high myopia group (group A, -6.00～-9.75 D) and a super-high myopia group (group B, ≥-10.00 D) on the basis of preoperative spherical equivalent refraction. Uncorrected visual acuity (UCVA), refraction, best corrected visual acuity (BCVA), equivalent Simk, central corneal thickness, and corneal differences of the posterior surface were measured after surgery and during a 2-year follow-up period. Results Twenty-four months after surgery, 86 eyes (82.7%) in group A and 68 eyes (69.4%) in group B achieved an uncorrected visual acuity (UCVA) better than 20/25. Refraction within ±1.00 D was measured in 93 eyes (89.4%) in group A and 75 eyes (76.5%) in group B 24 months after surgery. Nineteen eyes in group A and 16 eyes in group B had an improved BCVA after surgery. However, 3 eyes in group A and 7 eyes in group B had worse postoperative BCVA. There was a significant difference between equivalent Simk at 1 month after surgery and 3, 6, 12 and 24 months after surgery in both group A and group B. After surgery, the corneal difference of the posterior surface in group B was higher than that of group A and there was a significant difference between the two groups. At 24 months, corneal haze in group B was more severe than in group A and there was a significant difference between the two groups (Mann-Whitney, U=4070.000, P=0.001). Conclusion LASEK was a safe, effective method for high and super-high myopia.