Evaluation of Contrast Sensitivity after Four Different Treatment Modalities Using OPTEC-Functional Vision Analyzer in Primary Open-Angle Glaucoma

PURPOSE: The purpose of the study is to evaluate the changes in contrast sensitivity (CS) after using the four different types of antiglaucoma eye drops in patients with primary open-angle glaucoma (POAG) by OPTEC-functional vision analyzer (FVA). METHODS: In this prospective study, eighty patients (80 eyes) with POAG were randomly divided into four groups. The groups were randomly received timolol maleate 0.5%, travoprost 0.004%, dorzolamide 2%, and brimonidine tartrate 0.2%. The medications were used in the eye that was randomly selected. The CS was assessed before and 15 min after the intervention by the FVA. The paired t-test was used to compare the difference between before and after the intervention. P < 0.05 was considered statistically significant. RESULTS: Fifteen minutes after the instillation of timolol maleate (Group A), the CS in three out of twenty patients at the spatial frequencies of 1.5, and 3 cycles per degree (cpd) was significantly decreased (P = 0.015). However, using travoprost (Group B) and dorzolamide (Group C), the CS in one out of twenty patients at low spatial frequencies (1.5 and 3 cpd) was decreased in the two groups, which was not statistically significant for these medications (P > 0.05). In Group D, after applying brimonidine tartrate, the CS in two out of twenty patients at the spatial frequency of 18 cpd was significantly decreased (P = 0.042). CONCLUSION: Our study showed that CS values at low and high spatial frequencies after applying timolol and brimonidine eye drops are temporarily reduced in patients with POAG.