Abstract
PURPOSE: The aim of this study was to compare fundus blue autofluorescence (BAF) images, indicating photoreceptor alteration, and indocyanine green angiography (ICGA), indicating retinal pigment epithelium (RPE) alteration, in multiple evanescent white dot syndrome (MEWDS) to investigate the initial damage location within the RPE-photoreceptor complex. DESIGN: Multicentric retrospective cohort study carried out across tertiary centers for retinal and inflammatory diseases in France. PARTICIPANTS: A total of 31 eyes affected by primary MEWDS were included. METHODS: Only primary MEWDS, with sufficiently high-quality images, were included, and their data were analyzed cross-sectionally at baseline and at the recovery phase, between 4 and 8 weeks. A standardized protocol was set up for measuring the areas affected by MEWDS on the late-phase ICGA and on BAF; this was always carried out by the same investigator. On 55° macular-centered images, both the BAF and ICGA areas were delimited and calculated in the FIJI/ImageJ Software and then compared with each other. The same process was used to compare macular areas bounded by a 6-mm diameter Early Treatment Diabetic Retinopathy Study circle centered on the fovea. MAIN OUTCOME MEASURES: Areas in mm(2) affected by MEWDS on BAF and ICGA. RESULTS: The median hypofluorescent area on ICGA (93.03 mm(2), interquartile range [IQR: 54.08-134.00]) was significantly larger than that affected on BAF (76.22 mm(2) [IQR: 43.65-122.20], P < 0.0001). The median damaged surface was 37.21% (IQR: 21.63%-53.61%) on ICGA vs. 30.49% (IQR: 17.15%-46.60%) on BAF (P < 0.0001). Regarding only the macular area, damage was also significantly larger on ICGA than in BAF (15.16 [9.55-24.08] mm(2) vs. 13.48 [4.87-17.82] mm(2), P < 0.0001). CONCLUSIONS: Our study showed that MEWDS lesions are more extensive in ICGA than in BAF, indicating a predominant RPE dysfunction. We therefore support the hypothesis that MEWDS is a primary retinal pigment epitheliopathy, causing reversible and nondestructive dysfunction of the RPE and photoreceptors. Our results support recent analysis of modern multimodal imaging. Further studies using en face OCT are needed to analyze the outer retinal layers and corroborate the hypothesis. FINANCIAL DISCLOSURES: The author(s) have no proprietary or commercial interest in any materials discussed in this article.