X-linked retinoschisis (XLRS) is an inherited retinal dystrophy caused by mutations in the RS1 gene, typically presenting in young males with bilateral foveal schisis and variable peripheral involvement. We report the case of a 25-year-old male, the eighth of ten siblings, who presented with progressive diminution of vision in both eyes over the past 6 months. His best-corrected visual acuity was 6/18 in the right eye and 6/60 in the left eye. Fundus examination showed classical foveal schisis and spectral-domain optical coherence tomography (OCT) confirmed multilayer schitic cavities, more extensive in the left eye. A younger brother also demonstrated OCT-documented bilateral retinoschisis but with better visual acuity, highlighting intrafamilial phenotypic variability. Genetic testing could not be performed due to financial constraints, underscoring the diagnostic challenges in the resource-limited settings where multimodal imaging is indispensable. The proband was started on topical dorzolamide and oral acetazolamide, but no functional or structural improvement has been observed so far. This case contributes to the expanding clinical spectrum of XLRS, emphasizes variability in phenotypic expression within the same family, and illustrates the limitations of current treatment options while pointing toward the potential of emerging gene-based therapies.
Shukla et al. (2026) studied this question.