The clinical efficacy of a topical dorzolamide in the management of cystoid macular edema in patients with retinitis pigmentosa

Cystoid macular edema (CME) is one of the common complications of retinitis pigmentosa (RP), and is responsible for patient complications such as blurred and reduced visual acuity and for subsequent atrophic changes in the fovea. The objective of this work was to evaluate the clinical efficacy of a topical dorzolamide (a carbonic anhydrase inhibitor) in CME associated with RP. Sixteen eyes of nine patients with CME secondary to typical forms of RP were included in the study. Baseline visual acuity, visual field, and optical coherence tomography (OCT) measurements were obtained for all patients. All patients used 1% dorzolamide three times daily in each eye. Patients underwent follow-up exams at 1, 3, and 6 months after treatment. The response to treatment was monitored by visual acuity and visual field measurement testing using the Humphrey Field Analyzer (HFA: the central 10-2 Program); in addition, foveal thickness was measured by OCT. Evaluation of macular sensitivity calculated by HFA as the average of 12 central points. Thirteen (81.3%) of 16 eyes showed a clear decrease in retinal thickness after treatment. Evaluation of macular sensitivity, calculated by HFA as the average of 12 central points (with the exception of foveal point data, showed an improvement of more than 1.0 dB in nine (56.3%) of 16 eyes. Moreover, both the mean deviation value and macular sensitivity were significantly improved. No severe side-effects were seen in any of the patients examined. The results demonstrated that a topical dorzolamide is effective for the treatment of CME in patients with RP, and that the positive treatment effects last for up to 6 months.