Hyperreflectivity of the outer portion of the outer nuclear layer seen on optical coherence tomography in some cases of NR2E3‐associated retinopathy

Abstract

Aims/Purpose: Bi‐allelic variants in NR2E3 are associated with Enhanced S‐cone Syndrome. Several features have been described on optical coherence tomography (OCT) including schisis, outer nuclear layer (ONL) thickening and ellipsoid zone thickening in some patients. We have observed that in some individuals, the outer portion of the ONL appears hyperreflective compared with the inner portion. We investigated the prevalence of this sign in our genetically confirmed patient cohort.Methods: The electronic genetic database of Moorfields Eye Hospital was searched for patients with molecularly confirmed autosomal recessive NR2E3‐retinopathy. Patients who had undergone macular OCT (Spectralis, Heidelberg Engineering) were included. The horizontal foveal scan from the right eye (at the first visit for which OCT was available) was examined. The presence or absence of the specific sign was noted, together with presence of other features including schisis, atrophy or scarring.Results: 33 patients from 29 unrelated families were included (mean (SD) age, 29 (17) years; range from 5 to 59 years). Of these, 7 (21%) showed some hyperreflectivity in the outer ONL. The mean (SD) age of these individuals was 18 (12) years. The mean (SD) age of the rest of the cohort was 32 (17) years. The difference was not quite statistically significant (p = 0.052). After exclusion of those with schisis, atrophy or scarring (n = 14), the proportion with the hyperreflectivity sign was 37% (7 of 19 patients). The difference in ages reached significance (p = 0.024).Conclusions: A significant proportion of patients (21–37%) with autosomal recessive NR2E3‐retinopathy show this sign. One limitation of this study is that the prominence of the sign is dependent upon the type of scan performed (more distinct on single line scans with greater averaging than on regular volume scans). Patients with the sign were younger on average, suggesting it may be more prevalent in earlier stages.