Author: Simon Neary (Ireland)
Co-authors: Duncan Rogers
Herein we describe the case presentation, differential diagnosis, and management of multiple evanescent white dot syndrome (MEWDS).
A 47 year old lady presented with a sudden onset right paracentral scotoma for one week. She denied photopsia. Her past ophthalmic history was significant for one episode of right acute anterior uveitis and a left inferior macula-on chronic retinal detachment repair by cryotherapy/scleral buckling 5 years previously. Her medical history included degenerative disc disease for which she took diclofenac. She was on no other medication. Review of systems was unremarkable. Vision was right 6/9 and left 6/6. Intraocular pressures, pupil responses and color vision were normal. Anterior segment exam was quiet and there was no vitritis in either eye. Fundus exam of the right eye revealed subtle multifocal, grey-white lesions in the posterior pole. The discs and vessels were normal. Fundus exam of the left eye was normal apart from evidence of previous retinal detachment repair.
Octopus visual fields were normal, with no blind spot enlargement. OCT revealed a focal disruption of the ellipsoid zone/interdigitation zone corresponding to the patients scotoma. Fundus auto fluorescence (FAF) showed multiple hyperautofluorescent dots which correlated with the white dots seen on fundoscopy. Fluorescein angiography (FA) revealed early punctate hyperfluorescence in a wreath-like pattern and late staining, in areas corresponding to the white dots. Based on the clinical picture, fundus appearance, and ancillary testing, particularly FAF finding, a diagnosis of MEWDS was made. The differential included acute macular neuroretinopathy (AMN), acute idiopathic enlarged blind spot syndrome (AIEBS), multifocal choroiditis and panuveitis (MCP), PIC, AZOOR, and sarcoidosis. Over the course of the following month the patients symptoms improved and no treatment was initiated. We continue to monitor her.
MEWDS is a rare, unilateral, self-limited disease of unknown etiology, characterized by multiple small white dots that spontaneously resolve over a period of months. Middl aged women are typically affected, with a flu-like prodrome in 50% of cases. Symptoms include sudden blurring of vision, paracentral scotomata, including an enlarged blind spot, and shimmering temporal photopsias. There are no systemic manifestations. Exam may reveal an afferent pupillary defect, a quiet anterior chamber, mild vitritis, vascular sheathing, and disc edema. The characteristic finding is the presence of multiple discrete grayish white spots at the level of the outer retina or retinal pigment epithelium (RPE) measuring 100 to 200 μm, typically concentrated in the macula, sparing thr fovea, which may have a granular appearance due to tiny white or yellowish-orange specks and a distorted or absent reflex. On FA the lesions show early punctate hyperfluorescence spots in wreath-like configuration that stain late. The clinical course of MEWDS is short, with most patients experiencing nearly complete visual recovery over a period of 1 to 2 months. The diagnosis is clinical, and there is no diagnostic laboratory test. As MEWDS is a self limited disease with an excellent visual prognosis, no treatment is needed.