Comparison of Primary and Secondary Forms of Multiple Evanescent White Dot Syndrome

Abstract

The aim of this study was to compare primary versus secondary forms of multiple evanescent white dot syndrome (MEWDS) at T0 (baseline) and T1 (1-4 months after the onset of symptoms).Methods: A total of 101 eyes in 100 patients were included in a multicentric retrospective study.Results: Secondary MEWDS was defined as MEWDS associated with underlying chorioretinal inflammatory pathologies, mainly multifocal choroiditis and punctuate inner choroidopathy. Patients with secondary MEWDS were older (P = 0.011). The proportion of women (P = 0.8), spherical equivalent (P = 0.3), and best-corrected visual acuity at T0 (P = 0.2) were not significantly different between the two groups. The area of MEWDS lesions on late-phase indocyanine green angiography was significantly smaller in secondary MEWDS (P = 0.001) and less symmetrical with respect to both horizontal (P = 0.003) and vertical (P = 0.004) axis. At T0, neither the clinical (P = 0.5) nor the multimodal imaging (P = 0.2) inflammation scores were significantly different between the groups. At T1, the multimodal imaging inflammation score was higher in secondary MEWDS (P = 0.021). Conclusion:In secondary MEWDS, outer retinal lesions are less extensive and located close to preexisting chorioretinal lesions. Mild signs of intraocular inflammation on multimodal imaging are more frequent in secondary MEWDS during recovery. These findings suggest that chorioretinal inflammation may trigger secondary MEWDS.

Primary Multiple Evanescent White Dot Syndrome and Multiple Evanescent White Dot Syndrome Secondary to Multifocal Choroiditis/Punctate Inner Choroidopathy

“…Some of their findings were consistent with ours, such as gender composition, BCVA and multimodal inflammation scores at baseline, time from onset to presentation, etc. 19 Yet the authors also found that the patients with primary MEWDS had older age, better BCVA, and lower multimodal inflammation scores during follow-up, which is inconsistent with this work. However, they included a mixture of many different triggers of secondary MEWDS, including MFC/PIC, CNV, ocular toxoplasmosis, birdshot chorioretinopathy, etc.…”

“…It is well-known that mild signs of intraocular inflammation are typical characteristics of both primary MEWDS and most inflammatory pathologies underlying secondary MEWDS, including MFC/ PIC. 1,19 Based on our observation, we believe that signs of intraocular inflammation have a limited role in helping identify primary MEWDS and MEWDS secondary to MFC/PIC.…”

“…A recent study by Serrar et al 19 also compared the primary and secondary forms of MEWDS. Some of their findings were consistent with ours, such as gender composition, BCVA and multimodal inflammation scores at baseline, time from onset to presentation, etc.…”

“…A multimodal inflammation scoring system proposed by Serrar et al 19 was used to evaluate the sever-ity of ocular inflammation of all patients. The scoring criteria are as follows: 1 score for vitritis defined as the presence of hyperreflective dots in the vitreous detected by OCT, 1 score for vasculitis defined as the presence of retinal vascular leakages seen in FA, and 1 score for papillitis defined as the presence of papillary leakage in FA.…”

“…2,4,[14][15][16][17][18] Among those, MEWDS secondary to MFC/PIC is the most common type. 19 In short, MEWDS could be either idiopathic (primary MEWDS) or triggered by the underlying retinochoroidal disorders (secondary MEWDS), which is most associated with MFC/PIC. 19 In this study, we aim to present and compare both the clinical features and the multimodal imaging (MMI) findings of primary MEWDS and MEWDS secondary to MFC/ PIC, hoping to provide some insights into this longstanding dispute over the differences between MEWDS and MFC/PIC.…”