Clinical study on photorefractive keratectomy for high myopia with mitomycin C

Abstract

AIM: To evaluate the efficacy, safety and stability of photorefractive keratectomy(PRK)for high myopia with 0.2g/L mitomycin C(MMC). METHODS: Totally 109 patients(201 eyes)after PRK were treated with intraoperative application of 0.2g/L MMC for 20 seconds. The recovery of cornea epithelium after surgery was regularly observed. The uncorrected visual acuity(UCVA), corrected distance visual acuity(CDVA), refraction, haze, complications and endothelial cell counts 1 month, 3, 6, 12 months after PRK were compared. RESULTS:The time of corneal epithelium recovery was 3.68±0.35 days. All eyes had a significant increase in UCVA. 12 months after surgery, 189 eyes(94%)achieved UCVA better than 1.0 and 153 eyes(76%)had a spherical equivalent(SE)within±0.5D. 7 eyes(3%)lost one line of CDVA. No one lost 2 or more lines of CDVA. Ninety-six percent eyes changed within±0.5D when comparing 3 month and 12 month. Postoperative endothelial cell density and coefficient of variability(CV)did not show a significant difference from preoperative measurements(P1=0.71; P2=0.83). Haze of grade 1 occurred in 12 eyes(6%)and haze between grade 0.5 and 1 existed in 189 eyes(94%)at 12 months. No eye developed haze over grade 2. No toxic effect and complications of MMC were found after surgery. CONCLUSION: PRK with intraoperative application of MMC for 20 seconds appears to be a safe and effective method for correction of high myopia.

Keywords

• photorefractive keratectomy
• high myopia
• mitomycin C