Multiple evanescent white dot syndrome and presentations similar to multiple evanescent white dot syndrome in other disorders: a narrative review.

Multiple evanescent white dot syndrome (MEWDS) is an inflammatory fundus disease primarily affecting the outer retina. It is characterized by transient yellow-white dots on the outer retina. Although the exact pathogenesis remains unclear, the progress in multimodal imaging (MMI) has enhanced our understanding of MEWDS. Most cases of MEWDS are idiopathic, lacking a definite cause, and can spontaneously recover; these are what we term classic MEWDS. Consequently, MEWDS is often referred to as the "common cold of the retina". Simultaneously, patients with other disorders may present with varying degrees of manifestations similar to MEWDS. The resemblance in clinical or imaging findings can lead to misdiagnosis and inappropriate treatment. These MEWDS - like presentations are actually caused by other systemic or ocular disorders with diverse mechanisms. Thus, they differ from classic MEWDS in certain aspects. Using the keywords "MEWDS-like" and "Secondary MEWDS", we searched for all relevant studies published in the PubMed database from January 2021 to January 2024. Subsequently, we retrospectively summarized the clinical and imaging characteristics of MEWDS, along with the manifestations in other diseases that resembled those of MEWDS, and compared classic MEWDS with these similar presentations. Based on our review, we classified such similar presentations under other conditions into two categories and summarized their features for differential diagnosis. We recommend paying close attention to patients suspected of having MEWDS, as there may be more serious systemic or ocular disorders that require prompt treatment.