The two types of the foveal granular reflex in MEWDS using en face OCT

Abstract

Purpose : Multiple evanescent white dot syndrome (MEWDS) is characterized by white dots from the posterior pole to the midperiphery. In addition to the white dots, some patients often present with a foveal granular reflex (FGR) in macula, but its morphology varies and is often unclear. In this study, we observed FGR in MEWDS in detail, classified them into two types, and examined their characteristics.

Methods : Retrospective observational case series. Fourteen eyes of 14 MEWDS cases (3 male,11 female) were studied. This study was limited to typical naïve cases and excluded recurrent cases, cases with a history of uveitis, and cases with difficult diagnosis of acute zonal occult outer retinopathy (AZOOR)-complex diseases. The presence of FGR was evaluated using fundus photographs and classified into micro-type and fused-type based on the morphology of FGR; those with both types were included in the fused-type. We evaluated initial logMAR visual acuity, refractive error, FGR morphology, posterior vitreous cells, and central choroidal thickness, as well as the retinal layer where the FGR was present, using OCT B scan and en face OCT. We also evaluated en face OCT in a normal group matched for age, gender, and refractive error.

Results : Eight of the 14 eyes were micro-type and seven were fused-type. OCT showed ILM-level hyperreflexia in the micro-type and hyperreflexia below the outer reticular layer and disruption of the ellipsoid zone (EZ) in the fused-type. Posterior vitreous cells were found in 7 of 8 micro-type eyes. The mean logMAR visual acuity was not significantly different between the groups with and without micro-type but was significantly (P=0.046) lower in the group with fused-type (0.47 ± 0.32) than in the group without (0.15 ± 0.32).
No differences in choroidal thickness or refractive error due to FGR morphology were observed.

Conclusions : Classification of FGR findings in MEWDS into micro-type and fused-type may help in understanding the pathogenesis of MEWDS by revealing differences in the principal loci of each pathology.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.