Microstructural changes of photoreceptor layers detected by ultrahigh-resolution SD-OCT in patients with autosomal recessive bestrophinopathy

Abstract

Purpose: To determine the changes in the microstructures of the photoreceptors in patients with autosomal recessive bestrophinopathy (ARB) by ultrahigh-resolution spectral-domain optical coherence tomography (UHR-SD-OCT). Methods: Five eyes of 4 patients with ARB were studied. Cross-sectional images of the fovea were recorded by the UHR-SD-OCT system with a depth resolution of <2.0 μm. Results: The UHR-SD-OCT images revealed changes in the outer retinal structures that were dependent on the severity of the photoreceptor atrophy. There was an increase in the reflectivity and appearance of small hyperreflective dots (HRDs) in the outer segments, followed by an irregularity and decrease in the length of the outer segments, then a disruption of the ellipsoid zone (EZ) band, and appearance of large HRDs corresponding to the segmented ellipsoids. Finally, there was a disappearance of the large HRDs followed by a localized thinning of the outer nuclear layer and appearance of hyperreflective foci above the region of the disrupted EZ. Conclusions: UHR-SD-OCT can record images that show detailed changes of the microstructures of the photoreceptors at different stages of ARB. These observations should help in determining the mechanisms involved in retinal pathology and should provide important information on the effectiveness of treatments.

Keywords

• Autosomal recessive bestrophinopathy
• BEST1
• Interdigitation zone
• Ellipsoid zone
• Photoreceptor
• Spectral-domain OCT