Pain, wound healing and refractive comparison of mechanical and transepithelial debridement in photorefractive keratectomy for myopia: results of 1 year follow-up

Abstract

Purpose: To compare the efficacy, safety and postoperative pain of mechanical versus transepithelial photorefractive keratectomy (PRK) techniques.

Setting: Cornea and refractive surgery subspecialty.

Design: Prospective clinical trial.

Methods: This prospective comparative study included 84 eyes of 42 patients with myopia who received mechanical PRK (m-PRK) in 1 eye and transepithelial PRK (t-PRK) in the contralateral eye. The mean patient age was 28.5±6.3 years (range 20-46 years). Postoperative uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refractions, postoperative epithelial healing time, surgical time, postoperative pain rating and corneal haze were recorded.

Results: At week 1, statistically the UDVA was significantly better in the t-PRK eyes; however, at 3 months, similar refractive stability was achieved in both groups. The mean spherical equivalent (SE) decreased from -2.44±1.00D (m-PRK eyes) and -2.88±1.24D (t-PRK eyes) at baseline to -0.19±0.38D and -0.30±0.40D, respectively, after 1 year. Surgical time was 98.6±9.8s in m-PRK eyes and 58.0±6.4s in t-PRK eyes. On postoperative days 1 and 3, using the global assessment rating, 81% of mPRK eyes that had pain, reported more pain than that reported for the tPRK eyes. In addition, m-PRK treated eyes demonstrated higher mean pain scores based on the 11-point numerical rating scale and Visual Analogue Scale (VAS). The mean time to complete epithelial healing was 2.19±0.39 days (t-PRK) and 3.76±0.43 days (m-PRK).

Conclusion: t-PRK for mild-to-moderate myopia was more comfortable than conventional m-PRK; patients had less pain, and faster healing time.

Keywords: Cornea; LASER; Photorefractive keratectomy.