Purpose: To investigate the pathogenesis of Multiple Evanescent White Dot Syndrome (MEWDS) using multimodal imaging (MMI).
Methods: Retrospective case series of 7 patients with acute MEWDS. Each patient underwent: near-infrared reflectance (IR), blue and near-infrared autofluorescence (FAF and NIRAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), enhanced depth imaging optical coherence tomography (EDI-OCT) on Spectralis, and optical coherence tomography angiography on OCTA Spectralis, XR Avanti or Plex Elite 9000.
Results: OCTA and FA findings of early hyperfluorescence depict an unaffected choriocapillaris. On ICGA early to late hypofluorescent lesions corresponded to the hyporeflectivity on IR, consistent with altered reflectivity of the RPE. The SDI-OCT showed ellipsoid zone disruption as confirmed by FAF hyperautofluorescence. Some lesions showed a hypertransmission sign underneath the RPE, possibly due to changes in RPE intracellular melanin as suggested by NIRAF hypoautofluorescence.
Conclusions: The MMI findings of MEWDS are secondary to RPE reflectivity changes, suggesting its pivotal role.