Evaluation of the Efficacy Duration of Topical Therapies in Eyes with Primary Open-Angle Glaucoma

Background: To investigate the efficacy interval of the topical therapies available for primary open-angle glaucoma (POAG) and the ocular and systemic features potentially associated. Methods: This retrospective study included 190 patients with POAG undergoing first topical therapy, throughout a follow-up of 15 years. The patients started one topical intraocular pressure (IOP)-lowering drug within single molecules such betablockers, prostaglandin or dorzolamide, or fixed combinations such as betablockers + prostaglandin, betablockers + dorzolamide, or betablockers + brimonidine. Efficacy duration was measured as the time between the start of the therapy and the change due to IOP increase or visual field worsening. For each patient, ocular and systemic features and comorbidities were analysed to detect any significant correlation with the length of effectiveness of every drug used. Results: The molecules explored showed some discrepancies in terms of mean duration of efficacy; however, no significant differences were demonstrated (p > 0.05). Furthermore, when evaluating the overall cohort, no systemic or ocular features correlated significantly with the effectiveness of the molecules explored. However, the same analysis carried out upon stratifying the different groups according to the IOP-lowering drops they received, demonstrated that the drug efficacy could be influenced by several ocular and systemic features. Conclusion: Data observed in this study suggest that there is no difference in using one of the medications evaluated as first choice of treatment of POAG if the patients are accurately evaluated and the most recent guidelines are adopted.