Efficacy of corneal cooling on postoperative pain management after photorefractive keratectomy: A contralateral eye randomized clinical trial

Abstract

Purpose: To compare chilled and room temperature balanced salt solution (BSS) and bandage contact lens (BCL) on post photorefractive keratectomy (PRK) pain. Methods: In a prospective, single-masked, controlled eye study, one hundred eyes of fifty patients were divided into two groups which received room temperature or chilled BSS and BCL in each eye, and compared for post-PRK pain. Three different pain evaluation systems were used to evaluate pain between the groups at 1 and 6 h and days 1, 2, 3, 5, and 7, postoperatively. Results: 15 patients were male (30%), and 35 were female (70%). The mean age was 29 ± 5 (20–40) y/o. The mean spherical equivalent (SE) of preoperative refractive error in both groups was not statistically significantly different (−4.18 ± 1.5 in chilled and −4.19 ± 1.7 in room-temperature groups, respectively; P = 0.94). The mean time of epithelial healing was 6.16 ± 1.7 (3–13) days in the chilled and 6.10 ± 1.59 (3–12) in the room temperature group (P = 0.32). Best corrected visual acuity (BCVA) at 1 month was 0.013 ± 0.03 (0–0.22) logarithm of the minimum angle of resolution (logMAR) in the chilled group and 0.014 ± 0.04 (0–0.22) logMAR in the room temperature group, postoperatively (P = 0.84). No statistically significant difference was found between the two groups by any of the three pain scoring systems. No clinically important corneal haziness was found in the groups during follow-up. Conclusion: Chilled BSS and BCL do not seem to be superior to room temperature in reducing post-PRK pain. Keywords: Photorefractive keratectomy, PRK, Balanced salt solution, Bandage contact lens, Cooling, Pain