Abstract
Purpose :
Mutations in the nuclear receptor transcription factor NR2E3 manifest as autosomal recessive enhanced S-cone syndrome (ESCS), autosomal recessive retinitis pigmentosa (ARRP), or autosomal dominant retinitis pigmentosa (ADRP). ESCS is characterized by retinal dysplasia, degeneration, and the absence of rod photoreceptors. This retrospective, observational case series examines the retinal structure and lamination, within and outside the macula, in NR2E3 retinopathy.
Methods :
Clinical examination, electroretinography (ERG), fundus color and autofluorescence (AF) images, and optical coherence tomography (OCT) scans at the macula, nasal to the disc, and anterior to the vascular arcades were examined in ten patients (age range 13–57 years) with molecularly ascertained NR2E3 retinopathy. OCT scans at the same locations were obtained from seven healthy controls.
Results :
Seven patients had ESCS, one had ARRP, and two had ADRP (best corrected visual acuity 20/25–20/500). Five patients had ERG features in keeping with ESCS, and five patients had undetectable ERG. Fundus photographs showed a featureless retina in one patient with ESCS; and perimacular outer retinal atrophy with intra-retinal pigment migration in six patients with ESCS; and diffuse bone-spicule pigmentation in ARRP. Both patients with ADRP showed outer retinal atrophy with mild intra-retinal bone-spicule pigmentation. OCT scans anterior to the vascular arcades and nasal to the optic nerve head showed retinal thickening, abnormal lamination, and intra-retinal hyperreflective lesions in ESCS and ARRP. The OCT in ADRP showed relatively preserved retinal lamination with loss of the inner segment-ellipsoid zone outside of the central macula, and attenuation of the outer nuclear layer.
Conclusions :
This study demonstrates the value of OCT imaging of the extramacular retina in differentiating recessive and dominant NR2E3 retinopathies. The laminar disorganization associated with recessive NR2E3 retinopathy manifests in the regions that would have normally had high rod density; whereas the relatively preserved lamination in ADRP suggests normal retinal development. The mechanistic-structural differences between the two phenotypes give an insight into the pathophysiology of these disorders, and aid in selecting candidates for novel therapies.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.