Tear film in myopic patients with moderate dry eye before and after photorefractive keratectomy surgery

Abstract

Background: This study aimed to compare tear film in myopic patients with moderate and normal dry eye before and after photorefractive keratectomy (PRK) surgery. Methods: This was a prospective cohort study which used non-probability convenience sampling method. After running Schirmer's test I (without anesthesia), the patients undergoing PRK surgery were divided into two groups of normal and moderate dry eye. Inclusion criteria for mild to moderate myopic patients was between 2 to 5.5 diopters, without astigmatism or with astigmatism less than 2D which had refractive surgery criteria. Exclusion criteria included refractive surgery contraindications, taking ocular drugs, having dry eye and intensifying factors like smoking, working on computer more than 3 hours a day and repeated refractive surgery. A complete examination of patients was performed before the surgery and 3 months after the surgery, re-examination was performed and the results were evaluated. Findings: A total of 78 eyes (of 78 male and female subjects) with a mean age of 20-35 were evaluated. The patients were divided into two groups of 42 normal eyes and 36 moderate dry eyes. The two groups had no significant difference in terms of age, gender, spherical mean and corneal thickness. Schirmer 1 test average before the surgery was 28.64 ± 6.14 in the normal group and 8.36 ± 1.87 in the dry eye group. Three months after the surgery, the result was 24.64 ± 9.12 in the normal group and 6.17 ± 2.44 in the dry eye group. Conclusion: In corneal refractive surgery on both control group and moderate dry eye group, tears were reduced by 3 months after the surgery, but the risk of developing dry eye was higher in the moderate dry eye group. © 2016, Isfahan University of Medical Sciences(IUMS). All rights reserved.