Multiple evanescent white dot syndrome: clinical course and factors influencing visual acuity recovery

Objective: To report the demographics and the clinical course of patients with multiple evanescent white dot syndrome (MEWDS) and to investigate for those factors which influence visual acuity (VA) recovery. Methods: This is a retrospective single-centre observational study. Electronic medical records and retinal imaging of patients with a diagnosis of MEWDS with a minimum follow-up of 3 months were reviewed. Patients were categorised into three groups according to the VA at presentation and at the last visit: group 1 >0.48 logarithm of the minimum angle of resolution (LogMAR), group 2 ≤0.48 and ≥0.18 LogMAR and group 3 <0.18 LogMAR. All patients had non-invasive multimodal imaging including optical coherence tomography, near-infrared reflectance imaging and blue fundus autofluorescence at presentation and during follow-up. Results: A total of 51 eyes from 51 patients (41 women, mean age 29.8±7.8 years) were included. Significantly more patients presented in the autumn (X2=8.69, p=0.034). The percentage of eyes recovering vision to 0.0 LogMAR or better was 80.3% (41/51). Worse presenting vision and young age at presentation were independent significant predictive variables for poorer final VA (p=0.002 and p=0.02, respectively). No imaging features were significantly predictive of complete versus incomplete recovery, but disc hyperfluorescence on fluorescein angiography was more common in those with incomplete recovery. Conclusions: Although the majority of cases have a benign prognosis, the clinical spectrum of MEWDS includes incomplete visual recovery. In our series, poor presenting VA and young age were associated with poor VA outcome. Further study is warranted to confirm these findings.