Retinal Dystrophy with Intraretinal Cystoid Spaces Associated with Mutations in the Crumbs Homologue (CRB1) Gene

Purpose: To report the occurrence of intraretinal cystoid spaces presumably due to retinal degeneration caused by CRB1 mutations, and the response to treatment with carbonic anhydrase inhibitors. Materials: Retrospective case series. Methods: We report four patients with retinal degeneration and intraretinal cystoid spaces due to CRB1 mutation. Of these patients, three were treated with topical carbonic anhydrase inhibitors. One of these three patients was changed to oral carbonic anhydrase inhibitor. Best corrected visual acuity and quantitative and qualitative macular optical coherence tomography results were recorded. Results: Three patients were compound heterozygous for CRB1 mutations, and one had two mutations one of which was not found in the father. A total of seven different mutations were detected. All patients treated with carbonic anhydrase inhibitors experienced an improvement in visual acuity and decreased central retinal thickness, except in one eye in which retinal thickness paradoxically increased. Conclusions: CRB1 mutations may be associated with intraretinal cystoid spaces. The use of carbonic anhydrase inhibitors can result in improved visual acuity in some patients.