An USH2A variant leading to isolated maculopathy: a novel phenotype

To describe examination and findings in a case of isolated maculopathy with genetic testing revealing an USH2A genotype.

A 65-year-old man was found to have slowly worsening central vision in both eyes over several years. Fundus examination showed parafoveal pigmentary changes with an otherwise normal peripheral exam in both eyes. Fundus autofluorescence revealed parafoveal hypofluorescence with surrounding ring like area of hyperfluorescence, with optical coherence tomography (OCT) showing retinal thinning and parafoveal photoreceptor loss. Multifocal electroretinography (ERG) demonstrated diminished central responses, with full field ERG showing normal scotopic response and reduced photopic responses. Genetic testing for retinal dystrophies revealed a homozygous pathogenic variant in USH2A c.10342G>A, p. Glu3448Lys.

USH2A-associated retinal dystrophy usually presents with a rod-cone phenotype. While reports of a cone-rod phenotype have been described, we present the first reported case of isolated maculopathy in USH2A-associated retinal dystrophy.