Conditions

What is Multiple Evanescent White Dot Syndrome (MEWDS)?

Multiple Evanescent White Dot Syndrome (MEWDS) is a rare, acute, unilateral, self-limited disease, affecting the posterior part of the eye.

The disease is more frequent in healthy middleaged females aged 15-50 and can be preceded by a flu-like illness.

MEWDS classically manifests with multiple, whitish lesions located deep in the central area of the retina (macula), appearing as white dots.

The anterior part of the eye is usually not involved.

Mild inflammation of the vitreous (the jelly-like structure which fills the posterior cavity of the eye) which is known as vitiritis, and inflammatory involvement of the retinal vessels and optic disc can be detected.

An afferent pupillary defect, in which the pupil of the affected eye responds differently to light stimuli, can be present.

The white dots spontaneously resolve over a period of months.

What causes MEWDS?

The exact pathogenesis of MEWDS is unknown. However, an infectious trigger is thought to be involved in its pathogenesis since patients frequently report viral symptoms before the ocular involvement.

What are the symptoms?

Symptoms include a sudden, painless, unilateral decrease in vision, manifesting as

Diagnosis

There are no diagnostic laboratory tests and the clinical presentation of MEWDS is usually sufficient to confirm the diagnosis.

Dye tests, including fundus fluorescein angiography and indocyanine green angiography, are sometimes carried out to confirm the clinical suspicion. The retinal function can be measured by special tests, including visual fields and electrodiagnostic tests.