Multiple evanescent white dot syndrome (MEWDS) is a rare, acute, multifocal, retinitis located at the posterior pole that occurs predominantly in young to middle-aged females. Patients may report photopsia, central scotoma or decreased vision. The cause is generally unknown and the condition is self-limiting with a favorable prognosis for visual recovery within several weeks.


Department of Ophtalmology, Centro Hospitalar e Universitário de Coimbra, Portugal.


A case report is presented. Information from the clinical process, patient observation and complementary diagnostic exams was used to describe the case.


Woman, 41 years old, presenting with acute painless vision loss in her left eye (LE) associated with shimmering photopsias in the temporal visual field. Ophthalmologic examination at presentation consisted of: best corrected visual acuity (BCVA) right eye (RE): 10/10, BCVA LE: 1/10; unremarkable pupillary light reflex, ocular motility, biomicroscopy RE/LE and fundus examination RE. Fundus examination of the LE revealed a fovea with granular appearance and multiple white dots in the perifoveal area. Left fluorescein angiography demonstrated early and late punctate hyperfluorescence in the macula. The left visual field revealed an enlarged blind spot and global visual field loss. The amplitude of all components in left focal ERG (a and b wave) was reduced. The patient was followed for two months, during which left eye vision improved to 20/20 without treatment. At fundus examination the retinal lesions persisted although less pronounced. The visual field improved substantially and the ERG returned to normal.


Careful ophthalmoscopy and angiographic interpretation with complete patient history are the keys to the diagnosis of MEWDS. Ancillary testing including electroretinogram, early receptor potential and visual fields help in the differential diagnosis. No specific treatment is required. Recurrence is uncommon but has been reported in 10 to 15 percent of patients. Prognosis for patients with recurrences is also excellent. Choroidal neovascularization is a rare late complication of MEWDS and may require treatment.