Efficacy of dorzolamide in improving ocular blood flow in patients with open-angle glaucoma: The Indian carbonic anhydrase inhibitor trial

Purpose: Impaired ocular blood flow is an important risk factor in the pathogenesis of open-angle glaucoma (OAG). Studies have reported that dorzolamide 2% may be effective in improving ocular blood flow (OBF) in OAG patients. The objective of this study was to determine the efficacy of dorzolamide 2% (DORZOX, Cipla Ltd.) in improving retrobulbar blood flow in an Indian setting. Methods: The study was conducted as an interventional pilot project in 24 healthy subjects and 19 OAG patients. Baseline OBF measurements were done for all glaucoma patients with color Doppler imaging (CDI). Baseline ocular perfusion pressure (OPP) was calculated for all participants. Glaucoma patients were given dorzolamide 2% thrice daily for 12 weeks. The primary efficacy endpoints were mean changes in the CDI parameters of the retrobulbar vessels and OPP posttreatment. The secondary endpoint was mean change in the intraocular pressure (IOP) and adverse events, if any. Results: In comparison to healthy subjects, glaucoma patients displayed significantly reduced baseline OPP (P = 0.002). Treatment with dorzolamide 2% for 12 weeks led to a significant increase in OPP (P < 0.001) and a significant increase in end diastolic velocity (EDV) in all major ophthalmic arteries like ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary artery (SPCA) (P < 0.001, P = 0.04, and P = 0.0075, respectively). A significant reduction in the intraocular pressure (IOP; P = 0.007) was observed posttreatment, with no adverse events reported. Conclusion: Dorzolamide 2% significantly improved parameters such as the EDV and OPP in major ophthalmic arteries. This pilot study shows promising results on using dorzolamide for treating Indian patients with OAG.