• MEWDS Misdiagnosis Is Common

    By Jean Shaw
    Selected By: Andrew P. Schachat, MD

    Journal Highlights

    Ophthalmology Retina, September 2021

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    Using a large single-center cohort, Ramakrishnan et al. evaluated the clinical and imaging characteristics of multiple evanescent white dot syn­drome (MEWDS). They reported that although a distinct set of clinical exam and imaging findings permit recogni­tion of this rare condition, misdiagno­sis often occurs.

    For this retrospective study, the researchers assessed the medical records of 111 patients who were diagnosed with MEWDS in the Kaiser Permanente Northern California system between 2012 and 2019. Main outcome measures were patient characteristics, visual acuity (VA), clinical examination and imaging findings, and final diagnosis.

    Of the 111 patients, 73 were confirmed to have MEWDS, nine were excluded for inadequate imaging, and 29 were classified as misdiagnosed. Of the 73 confirmed to have MEWDS, 58 were female, with a mean (standard deviation [SD]) age at presentation of 35.2 (14.2) years and a mean refractive error of –1.6 D. Initial mean (SD) VA was logMAR 0.39 (0.31); this improved to mean (SD) logMAR 0.07 (0.15) at final follow-up. Presenting symptoms included blurred vision, scotomas, photopsias, and floaters. Nine patients had a previously diagnosed autoimmune disease, and two patients had been recently vaccinated (one for influenza, the other for the human papillomavirus).

    Clinical exam and imaging results indicated that all of the correctly diagnosed patients had ellipsoid zone disruption. Other common findings were white fundus lesions (67 patients), foveal granularity (54 patients), and hyperfluorescence on fluorescein angiography (45 patients). Both optic disc edema and vitreous cell were noted clinically or from angiography in ap­proximately half of cases. Of note, the authors pointed out that, in some cases, foveal granularity can be the only pre­senting feature of MEWDS. They also noted that although most patients were young, some were as old as 75 years.

    Of the 29 patients who were initially misdiagnosed, the ultimate diagnosis was typically a different type of infec­tious or inflammatory chorioretinal disease, including punctate inner choroiditis, syphilis, and primary vitreoretinal lymphoma. This high rate of misdiagnosis reflects the diagnostic challenge that MEWDS presents, the authors said, and they urged clinicians to consider other sight- and life-threat­ening diagnoses when patients present with uncommon retinal findings.

    The original article can be found here.