Evaluation of the Effects of Topical Prostaglandins on the Ocular Surface and Conjunctival Epithelial Thickness by SD-OCT: Case-Control Study

Objective: To evaluate the effect of topical latanoprost and latanoprost timolol combination (LTC) on conjunctival epithelial thickness and ocular surface discomfort in patients with primary open angle glaucoma. Material and Methods: The study included 43 patients in latanoprost group, 32 patients in LTC group, and 39 healthy subjects in control group. Bulbar conjunctival epithelial thickness was measured in all participants using spectral domain optical coherence tomography (SD-OCT) with ante rior segment module. Ocular Surface Disease Index® (OSDI®) score, Schirmer’s test with anesthesia and tear break-up time were recorded and compared between groups. Results: Mean conjunctival epithelial thickness was 31.27±3.85 µm in latanoprost group, 34.75±3.38 µm in LTC group and 39.20±4.85 µm in control group. Conjunctival epithelial thickness was sig nificantly lower in both latanoprost and LTC groups compared to control group (p<0.001). Mean conjunctival epithelial thickness was significantly lower in latanoprost group than in LTC group (p=0.001). OSDI® score was 33.02±18.80, 28.92±19.79 and 4.92±7.16 in latanoprost, LTC and control groups, respectively. OSDI® score was significantly higher in both la tanoprost and LTC groups compared to control group (p<0.001). Mean tear break-up time was significantly lower in both latanoprost and LTC groups compared to control group (p<0.001). Schirmer’s level wasn’t significantly different between groups (p=0.640). Conclusion: Use of preservative-con taining latanoprost and LTC reduces conjunctival epithelial thickness and impairs ocular surface discomfort by affecting tear stability. SD-OCT can be used to assess anatomy of conjunctiva and conjunctival epithelium before glaucoma surgery.