Clinical characteristics of multiple evanescent white dot syndrome with poor visual prognosis in Japanese patients

Multiple evanescent white dot syndrome (MEWDS) typically resolves spontaneously and is expected to have a favorable visual prognosis. Therefore, the initial manifestations of MEWDS have yet to be well studied. This study aimed to investigate the clinical characteristics of primary and secondary MEWDS patients and evaluate factors responsible for poor visual prognosis.

The medical records of 36 patients diagnosed with MEWDS between 2004 and 2021 at Hokkaido University Hospital were retrospectively reviewed. The study evaluated patient demographics, clinical characteristics, and multimodal imaging findings. The clinical factors involving final logMAR best-corrected visual acuity (BCVA) were analyzed. In addition, clinical characteristics of secondary MEWDS cases with poor visual prognosis were investigated.

Twelve of the 36 patients (33.3%) had active chorioretinal lesions distinct from MEWDS lesions, resulting in a prevalence of secondary MEWDS of 33.3%. Four patients presented with foveal active chorioretinal lesions (11.1%). Retinal atrophy developed in these lesions in all four cases during the follow-up period. Compared to primary MEWDS, secondary MEWDS with foveal involvement of active chorioretinal lesions was associated with significantly worse visual acuity at the initial visit (p = 0.004), and showed a trend toward poorer visual acuity was also observed at the final visit (p = 0.11). In simple linear regression analysis, coexisting foveal involvement of active chorioretinal lesions was significantly associated with worse final logMAR BCVA (p = 0.002). In multiple stepwise linear regression analysis, coexisting foveal involvement (p < 0.001) and male sex (p = 0.03) remained independently associated with poorer visual outcomes.

The presence of foveal active chorioretinal lesions in MEWDS may be associated with poorer visual prognosis.

WHAT IS KNOWN : • Recent reports characterized the clinical aspects of primary and secondary multiple evanescent white dot syndrome (MEWDS), but the visual prognosis of these variants is only slowly unfolding.

• Secondary MEWDS associated with foveal involvement of active chorioretinal lesions had significantly poorer visual acuity at the initial visit and showed a trend toward poorer visual acuity at the final visit compared to primary MEWDS. • In both simple and multiple linear regression analyses, foveal involvement of active chorioretinal lesions was associated with poorer visual outcomes. • The presence of foveal active chorioretinal lesions in MEWDS may be associated with poorer visual prognosis.