Loss of Foveal Cone Photoreceptor Outer Segments in Occult Macular Dystrophy.

To describe a previously unreported finding on optical coherence tomography (OCT) in a patient with occult macular dystrophy (OMD) and correlate it with retinal dysfunction. Retrospective observational case report. A 72-year-old woman presented with sequential progressive central scotomata with reduced visual acuities and color vision in both eyes. Fundoscopic appearance, fundus autofluorescence, fluorescein angiography, and indocyanine green angiography were normal. Full-field ERG was normal, but multifocal ERG demonstrated reduced amplitudes, confirming the diagnosis of OMD. OCT demonstrated loss of cone outer segments with preservation of the inner segment-outer segment junction and photoreceptor cell bodies in both eyes. Loss of cone photoreceptor outer segments may be responsible for decreased visual acuity and foveal thinning in OMD.