Effect of the pre-photorefractive keratectomy Schirmer value on the post-photorefractive keratectomy central epithelial thickness, ocular surface disease index scores, and uncorrected visual acuity

Purpose: The aim of the present study was to investigate the effect of the pre-photorefractive keratectomy (PRK) Schirmer value on the post-PRK central epithelial thickness (CET), Ocular surface disease index (OSDI) scores and uncorrected visual acuity (UCVA). Methods: After the exclusion of patients, 106 patients were analyzed (n = 54 for control group; n = 52 for dry eye group). Best corrected visual acuity levels, detailed anterior segment and fundus examinations of the patients, intraocular pressures were recorded. Corneal thickness measurements were performed. Tear film break-up time (BUT) and Schirmer’s tests were applied to all patients. The OSDI questionnaire was administered to all patients at the third month after the operation. The patients were divided into two groups according to the preoperative Schirmer’s value as follows: control group (preoperative Schirmer value over 10 mm) and dry eye group (preoperative Schirmer 1 value between 0–10 mm). After the surgical procedure, the measurements and questionnaire were repeated. Results: The mean OSDI score and CET value increased significantly in dry eye group at the third month after the operation compared to the preoperative period (P < .001). After PRK, UCVA does not show a significant difference between groups. Conclusion: Laser surgery affects the corneal epithelial thickness in some patients and reduces visual comfort. Thus, it can be suggested that dry eye should be treated preoperatively, followed by PRK.