Multimodal fundus imaging in fundus albipunctatus with RDH5 mutation: a newly identified compound heterozygous mutation and review of the literature

Abstract

The aim of this study was to describe multimodal retinal imaging of fundus albipunctatus (FA) with the newly identified compound heterozygous RDH5 mutation and to review the relevant literature. Five family members were examined, and the RDH5 gene was analyzed by direct sequencing. The clinical features and genetic study of FA are reviewed. The proband had a compound heterozygotic missense mutation of Cys59Ser (TGC → AGC) and a nonsense mutation of Trp95ter (TGG → TGA) in the RDH5 gene. Fundus examination revealed diffuse yellow flecks with foveal sparing. Infrared reflectance (IR) imaging showed multiple discrete round lesions, and fundus autofluorescence (FAF) imaging showed decreased autofluorescence. In spectral domain optical coherence tomography (SD-OCT), the lesions spanned across the retinal pigment epithelium complex and the photoreceptor inner segment ellipsoid band. The outer nuclear layer thickness is decreased compared to normal control. Electroretinography (ERG) showed improved dark-adapted responses after a prolonged 2.5-h dark adaptation. The fundi of the patient's son and daughter both appeared unremarkable. The clinical findings, differential diagnosis, and genetic studies of these features are reviewed. This is the first time that IR imaging of this disease has been reported; IR imaging showed more detail than did FAF imaging. Although retinal imaging (fundus photographs, FAF, IR, SD-OCT) of FA showed characteristic findings, ERG and genetic study remain the most reliable tests for making the diagnosis.