Swept source optical coherence tomography and optical coherence tomography angiography in pediatric enhanced S-cone syndrome: A case report

Background: Enhanced S-cone syndrome is an autosomal recessive retinal dystrophy related to a defect in a nuclear receptor gene (NR2E3) that leads to alteration in cells development from rod to S-cone. This retinal dystrophy may be associated with retinal schisis. The aim of this report is to describe structural optical coherence tomography and optical coherence tomography angiography features in a case of enhanced S-cone syndrome associated with macular schisis. Case presentation: A Caucasian 13-year-old girl underwent measurement of best corrected visual acuity, ophthalmoscopic evaluation, and fundus autofluorescence examination. Photopic and scotopic electroretinography were carried out as well. Enhanced S-cone syndrome was suspected on the basis of clinical and electrophysiological findings. Structural optical coherence tomography and optical coherence tomography angiography allowed the further characterization of the associated macular schisis. Genetic analysis not only confirmed the diagnosis but increased the clinical novelty of this case report by showing two variations in the NR2E3 gene probably related to the phenotype: a missense variation c.1118T>C which leads to the substitution of leucine with proline in amino acid position 373, and c.349+5G>C, which involves a gene sequence near a splicing site. Conclusions: Swept source structural optical coherence tomography (B scans and "en face" images) and optical coherence tomography angiography allowed the observation of retinal structural details and the involvement of each retinal layer and capillary plexus in enhanced S-cone syndrome. Of interest, neither of the two NR2E3 gene variants found in this case report have been linked to any form of retinopathy.