Efficacy of Topical Carbonic Anhydrase Inhibitors in Reducing Duration of Chronic Central Serous Chorioretinopathy

PURPOSE: Topical carbonic anhydrase inhibitors (CAIs) can influence retinal fluid distribution, but their role in treating central serous chorioretinopathy (CSCR) has not been studied. We examined the efficacy of a topical CAI (dorzolamide) in treating chronic CSCR. METHODS: Prospective, nonrandomized, controlled intervention study of patients with chronic CSCR of at least 3 months duration. Observed controls (n = 15) were recruited consecutively from 2016 to 2017; treated cases (n = 18) were recruited from 2018 to 2019. Controls were observed without active intervention, whereas treated cases were treated with topical dorzolamide for 3 months. The study end points were change in central macular thickness (CMT), change in best corrected visual acuity (BCVA), and proportion of eyes achieving complete resolution of subretinal fluid (SRF). All end points were at 3 months. RESULTS: Treated patients who received topical CAI had greater reduction in CMT (−145.6 µm, 95% confidence interval [CI] −170.5 to −120.7) compared to observed controls (−45.1 µm, 95% CI −65.3 to −25.1) at the main study end point of 3 months (P = 0.015). A higher proportion of treated patients achieved complete resolution of SRF compared to observed controls (77.8% vs. 40.0%, P = 0.04) at 3 months. However, change in BCVA at 3 months was similar in both groups (P = 0.12). CONCLUSIONS: Topical CAI resulted in more rapid reduction of CMT compared to observation. These results, if confirmed in other studies, suggest topical CAI may be a viable treatment option for patients with chronic CSCR. TRANSLATIONAL RELEVANCE: Topical CAI is used to treat a number of retinal disorders, and may be a novel treatment option for chronic CSCR.