Multimodal Imaging in Atypical Cases of Multiple Evanescent White Dot Syndrome

Abstract

 

Purpose

 

To describe atypical cases of Multiple Evanescent White Dot Syndrome (MEWDS) with foveal exudation and choroidal thickening (pachychoroid).

 

Methods

 

Three cases of MEWDS were studied at a Retina referral center. The patients underwent evaluation with multimodal imaging including spectral domain and enhanced depth imaging optical coherence tomography (OCT).

 

Results

 

Three patients presented with acute onset, painless, decreased central vision. One of the patients additionally presented with photopsia and visual field defect. There were 2 women and 1 man included in this study. The average age was 24 years. Visual acuity at presentation was on average 1.47 Logmar (20/590 Snellen equivalent). All cases had fundus findings consistent with MEWDS in color, indocyanine green angiography (ICGA), fluorescein angiography (FA), short wavelength autofluorescence (SW-AF) and OCT imaging. All cases were unilateral; OD was affected in 1 patient and OS in 2 patients. On OCT, all 3 patients were noted to have a hyper-reflective foveal exudate above the retinal pigment epithelium (RPE) and a pachychoroid (mean = 432 microns). Color images of the fovea showed a yellowish exudate. FA and ICGA showed foveal exudation without choroidal neovascularization (CNV). In one patient, choroidal thickness decreased to 153 microns following resolution of the acute lesion. However, the foveal exudate condensed into a fibrotic scar and the visual acuity remained limited at 1 Logmar (20/200 Snellen equivalent). Follow up of another one of the cases showed development of CNV in the area where the exudative material was present. The CNV was treated with bevacizumab and responded well.

 

Conclusions

 

Although MEWDS is most often a self-limited disease, a minority of patients may have persistent decreased vision. Similar to other diseases such as central serous chorioretinopathy and pachychoroid pigment epitheliopathy, choroidal thickening may predispose to an exudative process. These exudative changes may increase the risk for permanent fibrosis and/or secondary CNV resulting in permanent visual loss following resolution of the acute inflammatory process.  

 

Case 1: A. Color photo of a patient with MEWDS with an exudate at the fovea. B. Corresponding OCT image with foveal exudate above the RPE and a thick choroid. C. Color photo of the same patient 8 months later. D. OCT image at 8 months follow up showing fibrous scar.