We read with interest the article on efficacy of topical dorzolamide therapy for cystic macular lesions in patients with retinitis pigmentosa (RP) and Usher syndrome.1 The authors report that topical dorzolamide is effective in decreasing central foveal thickness and improving visual acuity in some patients with RP and cystoid macular edema (CME). A subset of patients with RP develop cystoid maculopathy, macular cysts that can be confused with CME on ophthalmoscopy and optical coherence tomography (OCT). This phenotype has been noted in Goldmann-Favre syndrome, enhanced S cone syndrome, and clumped pigmentary retinal degeneration, all of which were associated with mutations in the NR2E3 gene.2 While optical coherence tomography is useful in documenting this maculopathy,3 this subset of retinal dystrophies also demonstrates hypersensitivity to short-wavelength light flashes on electroretinography (ERG).4 Intravenous fluorescein angiography (IVFA) establishes the cavitary nature of the maculopathy, with no hyperfluorescence seen on angiography compared with leakage seen in patients with CME and RP.5