Association of Retinal Artery and Other Inner Retinal Structures With Distribution of Tapetal-like Reflex in Oguchi's Disease.

Abstract

To report novel ophthalmoscopic features of patients with Oguchi's disease, and to describe how they may be related to the unusual tapetal-like fundus appearance. Twenty-one eyes of 11 patients who were diagnosed with Oguchi's disease were investigated. Genetic screening of seven cases showed homozygous mutations in the SAG gene (c.926delA). The retinal appearance was retrospectively assessed in the fundus photographs, and the optical coherence tomographic (OCT) and fundus autofluorescence (AF) images. In 11 eyes of 7 patients, clearly demarcated dark regions without tapetal-like reflex were observed in the midperipheral retinal regions. In the dark regions, OCT showed lower reflectances in the photoreceptor layer but the AF images had normal reflectances. In nine eyes of six patients, the dark regions were partially demarcated by retinal arteries but not by veins. In nine eyes of five patients, the extent of the dark regions either increased or decreased during the course of the disease process, and these changes were not due to the state of adaptation or a posterior vitreous detachment. In all eyes, the peripheral retinal arteries but not veins had either high or low reflective regions along one side. Although the alterations of the outer retinal layers are believed to be most responsible for the abnormal tapetal-like reflex in patients with Oguchi's disease, these ophthalmoscopic features cannot be explained solely by the abnormality of the outer retina. Our findings suggest that the appearance of tapetal-like reflex is strongly affected by alterations of structures in the inner retinal layers.