TRANSEPITHELIAL VERSUS CONVENTIONAL PHOTOREFRACTIVE KERATECTOMY. VISUAL RECOVERY, SPHERICAL ABERRATION AND DENSITOMETRY: A RANDOMIZED CONTROL TRIAL

This study aims to compare postoperative pain, photophobia, corneal epithelial healing, visual acuity, spherical aberration, and corneal haze (densitometry) between transepithelial photorefractive keratectomy (tPRK) and conventional manual PRK (mPRK).

Armed Forces Hospital, Muscat - Oman

A prospective, single-blinded randomized controlled trial was conducted at Armed Forces Hospital, Muscat. Participants were randomly assigned to undergo either tPRK or conventional mPRK. Postoperative pain and photophobia were evaluated using a 0 to 10 scale, while corneal healing was assessed through clinical examination. Distance visual acuity was measured, and Pentacam^© was used to analyze spherical aberration and corneal densitometry. Baseline parameters were recorded preoperatively, with follow-up visits conducted on days one, four, and eight, and at first, third, and sixth months postoperatively.

A total of 79 patients (158 eyes) were included in the study, with each group comprising 79 eyes. Both groups showed similar pain levels over the eight-day postoperative period, except on the day of surgery, where the tPRK group reported significantly higher pain levels than the conventional mPRK group (median pain score 7.0 vs. 5.0; p = 0.004). There were no significant differences in photophobia between the two groups (p > 0.05). Epithelial healing was faster in the tPRK group, with 67.1% of eyes achieving complete healing by day four, compared to 36.7% in the mPRK group (p < 0.001). Visual acuity outcomes were similar in both groups over the six-month follow-up, except at the first-month visit, where the tPRK group demonstrated better-uncorrected distance visual acuity (1.0 vs. 0.9; p = 0.029). Spherical aberration increased significantly in the tPRK group at the sixth-month postoperative visit (0.469 vs. 0.322; p < 0.001). Densitometry values did not show significant changes over the six months in either group, though a slight increase was observed at the first-month visit, with a more pronounced rise in the mPRK group. However, this difference was statistically insignificant.

The tPRK offers comparable visual outcomes with faster epithelial healing to mPRK, although it may result in higher initial postoperative pain and increased spherical aberration.