Fundus autofluorescence and photoreceptor bleaching in multiple evanescent white dot syndrome

The authors present three cases of multiple evanescent white dot syndrome (MEWDS) with characteristic fundus autofluorescence (FAF) findings, including one patient without any visible white dots on funduscopic examination and another with many more hyperautofluorescent lesions than seen ophthalmoscopically. Additionally, the findings support an alternative mechanism for the hyperautofluorescent lesions in MEWDS, whereby photoreceptor loss causes unmasking of normal underlying retinal pigment epithelium autofluorescence. This hypothesis is demonstrated in two cases by optical coherence tomography showing clear ellipsoid zone attenuation with registration to hyperautofluorescent lesions. It is further supported in two cases by photoreceptor bleaching in successive FAF images captured in the same session leading to diminished autofluorescence intensity of the characteristic dots.