Case of cone dystrophy with normal fundus appearance associated with biallelic POC1B variants

ABSTRACTBackground: Biallelic variants of POC1B were recently reported to cause autosomal recessive non-syndromic cone dystrophy. However, the number of studies supporting this is limited, and the clinical phenotypes of cone dystrophy have not been definitively determined. The purpose of this study was to report the phenotype of a case of POC1B-associated cone dystrophy.Materials and methods: The medical chart of one case diagnosed with cone dystrophy was reviewed.Results: The patient was a 20-year-old Japanese man whose chief complaint was a progressive decrease in his central vision. His decimal best-corrected visual acuity was 0.2 for the right and 0.3 for the left. Fundus examinations showed no abnormalities. The photopic electroretinograms were nonrecordable, but the scotopic electroretinograms were within normal limits. Optical coherence tomography detected a blurry line in the region of the external limiting membrane and ellipsoid zone. Adaptive optics images showed sparsely distributed cone cells ...