A 36-year old man was evaluated for a 10 year history of visual decline and 5 year history of gait, limb, and speech ataxia. His neurologic exam was remarkable for a wide based ataxic gait with appendicular, axial, and speech ataxia. His eye exam revealed saccadic pursuits and reduced visual acuity. Ophthalmoscopic evaluation of the fundus was remarkable for diffuse attenuation of the arterioles and minimal foveal fine pigmentary mottling. A full-field electroretinogram revealed abnormalities that tended to be more prominent in cone mediated responses. Visual field assessment showed increased blind spot and a left pericentral scotoma. Fluorescein angiography showed a small central window defect in the macula (Figure A). High-definition spectral domain optical coherence tomography (SD-OCT) showed the reason for the reduced visual acuity (Figure B).