Efficacy of Sustained Topical Dorzolamide Therapy for Cystic Macular Lesions in Patients with Retinitis Pigmentosa and Usher Syndrome

Objectives: To determine the efficacy for sustained use of topical therapy with dorzolamide hydrochloride 2% on visual acuity and cystic macular lesions in retinitis pigmentosa (RP) and Usher (USH) syndrome patients. Design: Retrospective case series. Setting: University hospital. Patients: Sixty-four eyes of 32 patients with RP or USH syndrome who received treatment with topical dorzolamide formulation for a duration ranging from 6-58 months were enrolled. Main Outcome Measures: Changes in visual acuity (ETDRS) and central foveal zone thickness on optical coherence tomography during follow-up for the duration of treatment. Results: Among the study cohort, a positive response occurred in 20 of 32 patients (63%) in at least one eye and in 13 patients (41%) in both eyes. Four patients (20%) showed an initial response and a subsequent rebound of macular cysts. In 8 patients (25%) there was no response to treatment and the macular cysts worsened when compared with the pretreatment level. Ten patients (31%) had improvement in visual acuity by ≥7 letters in at least one eye at the most recent follow-up visit. Sixteen patients (67%) showed a reduction of >11% in the central foveal zone thickness in at least one eye when compared with the pretreatment level. Conclusion: Treatment of cystoid macular edema with topical dorzolamide in patients with either RP or USH syndrome and followed by an OCT-guided strategy showed a decrease in central foveal zone thickness in the majority of cases. Visual acuity improved in almost 1/3 of the cases, suggesting a potential corresponding visual benefit.