Alternate day vs daily topical brinzolamide for the treatment of cystic maculopathy in inherited rod cone retinal degenerations

<b>Introduction:</b> Cystic maculopathy (CM) occurs in 10-50% of inherited rod-cone retinal degenerations (RCD), with carbonic anhydrase inhibitors reported to show improvement, but rebound may occur. Alternate day treatment with topical Brinzolamide may alleviate this effect. We assessed treatment response in alternate day vs continuous day dosing.<b>Methods:</b> A retrospective chart review of patients with RCD undertaken, identifying those with CM, recording treatment regimen, vision, and OCT parameters. Outcomes were visual acuity (VA) improvement ≥3 letters significant, OCT reduction of mean cyst size (CMT) ≥11% significant, and macular volume (MV).<b>Results:</b> Of 260 patients identified, 66 (25.3%) had CM; complete data were available for 22 patients (41 eyes) in Group 1 (alternate day) and 12 patients (22 eyes) in Group 2 (continuous). In group 1, VA improved in 29% patients, with significant CMT mean reduction of 16 μm (80% eyes). Group 2 VA improved in 13.6% patients, with significant CMT mean reduction of 34 μm (77% eyes). No statistical difference between groups was found with VA or MV. Mean CMT reduction was significant in Group 2, 21 μm (p-value 0.034) and VA improvement was better with alternate day treat- ment.<b>Discussion:</b> This study suggests both treatment regimens have similar functional outcomes, enabling a tailored and patient-centric approach to dosing.