Cone - Rod Dystrophy with OCT

This is a montage of images and electroretinographic (ERG) studies from a 58-year-old female patient who complained of progressive difficulty seeing in bright light and reading over four years. Her visual acuity was 20/50 right, 20/60 left. Her fundus examination was notable only for slight arteriolar narrowing. Fundus autofluorescence imaging with the OPTOS scanning laser ophthalmoscope showed a mild perifoveal ring of hyperflourescence (bracketed by red lines). A 10-2 visual field showed a central scotoma (red arrow). The yellow arrows on the OCTs highlight the irregularities of the photoreceptor ellipsoid zone layer. The teal arrows highlight the flat readings from the left eye ERG. The right eye showed reduced amplitudes, but signals were discernible. The diagnosis most compatible with all the findings is cone-rod dystrophy. The patient refused genetic testing to determine if a known mutation underlies her phenotype.