Objective: We investigated the efficacy of additional topical betamethasone in persistent cystoid macular oedema (CMO) after carbonic anhydrase inhibitors (CAIs) therapy.
Methods and analysis: This retrospective cohort study included 16 eyes of 10 patients with retinitis pigmentosa (RP). All patients were previously administered CAI for at least 3 months to treat CMO secondary to RP and lacking an effective reduction (≥11%) of central foveal thickness (CFT). We administered topical 0.1% betamethasone daily in each affected eye following a preceding course of the CAI medication as a first treatment. CMO was diagnosed using spectral-domain optical coherence tomography. CFT was regarded as the average of vertical and horizontal foveal thickness. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were obtained from patient medical records. We compared the CFT and BCVA between baseline and the average of 1-3, 5-7, 10-14 and 16-20 months period.
Results: In treatments with brinzolamide in 14 eyes, dorzolamide in 2 eyes and bromfenac in 2 eyes, CFT effectively decreased in 12 of 16 eyes (81%). CFT decreased significantly in 1-3 months (326±102 µm; n=16; P=0.029) and 5-7 months (297±102 µm; n=12; P=0.022) compared with baseline but not within 10-14 months (271±96 µm; n=9; P=0.485) or 16-20 months (281±134 µm; n=9; P=0.289). There were no significant intergroup differences in BCVA throughout the study. Betamethasone treatment was stopped in three patients because of IOP elevation.
Conclusion: Our data suggested that additional betamethasone might improve treatments for persistent CMO. Topical steroids could be an alternative option for managing persistent CMO in RP.
Keywords: drugs; retina; treatment medical.