Photoreceptor function and structure in retinal degenerations caused by biallelic BEST1 mutations. (February 2023)

• Record Type: Journal Article
• Authors: Cideciyan, Artur V.; Jacobson, Samuel G.; Sumaroka, Alexander; Swider, Malgorzata; Krishnan, Arun K.; Sheplock, Rebecca; Garafalo, Alexandra V.; Guziewicz, Karina E.; Aguirre, Gustavo D.; Beltran, William A.; Matsui, Yoshitsugu; Kondo, Mineo; Heon, Elise
• Is Part Of: Vision research. Volume 203(2023)
• Publication Date: 2023-02
• Subjects: Vision -- Periodicals; 573.88
• DOI: 10.1016/j.visres.2022.108157
• Languages: English
• ISSNs: 0042-6989

Abstract

Highlights: Detailed multimodal phenotype in patients with autosomal recessive bestrophinopathy. Prominence of external limiting membrane pointing to activation of glial cells. Perimacular regions with retained rod photoreceptors lack co-localized rod function. The kinetics of rod dark-adaptation is abnormally slow. Night vision-based outcome measures could show improvement with successful therapy. Abstract: The only approved retinal gene therapy is for biallelic RPE65 mutations which cause a recessive retinopathy with a primary molecular defect located at the retinal pigment epithelium (RPE). For a distinct recessive RPE disease caused by biallelic BEST1 mutations, a pre-clinical proof-of-concept for gene therapy has been demonstrated in canine eyes. The current study was undertaken to consider potential outcome measures for a BEST1 clinical trial in patients demonstrating a classic autosomal recessive bestrophinopathy (ARB) phenotype. Spatial distribution of retinal structure showed a wide expanse of abnormalities including large intraretinal cysts, shallow serous retinal detachments, abnormalities of inner and outer segments, and an unusual prominence of the external limiting membrane. Surrounding the central macula extending from 7 to 30 deg eccentricity, outer nuclear layer was thicker than expected from a cone only retina and implied survival of many rod photoreceptors. Co-localized however, were large losses of rod sensitivity despite preserved cone sensitivities. The dissociation of rod function from rod structure observed, supports a large treatment potential in the paramacular region for biallelic bestrophinopathies.