Imaging With Multimodal Adaptive-Optics Optical Coherence Tomography in Multiple Evanescent White Dot Syndrome: The Structure and Functional Relationship

Abstract

Purpose To elucidate the location of pathological changes in Multiple Evanescent White Dot Syndrome (MEWDS) with the use of multimodal adaptive optics (AO) imaging. Methods A five-year observational case study of a 24 year-old year old female with recurrent MEWDS. Full examination included history, Snellen chart visual acuity, pupil assessment, intraocular pressures, slit lamp evaluation, dilated fundoscopic exam, imaging with Fourier-domain optical coherence tomography (FD-OCT), blue-light fundus autofluroescence (FAF), fundus photography, fluorescein angiography, and AO-OCT. Results Three distinct acute episodes of MEWDS occurred during the period of follow-up. FD-OCT and AO imaging showed disturbance in the photoreceptor outer segments (PR OS) in the posterior pole with each flare. The degree of disturbance at the PR level corresponded to size and extent of the visual field changes. All findings were transient with delineation of the photoreceptor recovery from the outer edges of the lesion inward. Hyperautofluorscence was seen during acute flares. Increase in choroidal thickness did occur with each active flare but resolved. Conclusion Although changes in the choroid and RPE can be observed in MEWDS, FD-OCT and multimodal AO imaging localized the visually significant changes seen in this disease at the level of the PRs. These transient retinal changes specifically occur at the level of the inner segment ellipsoid and OS/RPE line. En face OCT imaging provides a detailed, yet noninvasive method for following the convalescence of MEWDS and provides insight into the structural and functional relationship of this transient inflammatory retinal disease.

Optical coherence tomography angiography in uveitis

“…OCTA is of great importance in revealing that within the corresponding hypofluorescent spots of ICGA, the choriocapillaris and retinal capillary blood flow are completely normal. This reinforces the concept that choriocapillaris may not be involved in this disease and the primary cause of it stands at the level of RPEphotoreceptor complex [1,23,[47][48][49] Acute posterior multifocal placoid pigment epitheliopathy FFA demonstrates early hypofluorescence of the acute posterior multifocal placoid pigment epitheliopathy (APMPPE) lesions and late hyperfluorescence due to staining [50][51][52]. APMPPE has been proposed to be a result of ischemia and acute inflammation of the choriocapillaris, but not of the medium and large sized choroidal vessels, leading to RPE abnormalities [53][54][55].…”

Swept-source OCT in patients with multiple evanescent white dot syndrome

“…The author hypothesized that the initial inflammatory process begins in the inner choroid and then spread to the entire choroid and outer retinal layers [ 13 ]. Conversely, several studies using SD-OCT have demonstrated that MEWDS starts in the outer retina and the photoreceptors, specifically in the EZ [ 17 – 19 ]. In their MEWDS series, Pichi et al [ 6 ] demonstrated that the choriocapillaris/choroid and superficial and deep retinal capillary networks were comparable to normal healthy controls.…”

Resolution of photoreceptor layer damage in multiple evanescent white dot syndrome

“…The clinical signs include deep outer retinal yellow-white lesions that are 100–200 μm in size and foveal granularity. [ 2 ] Fourier-domain optical coherence tomography (OCT) localizes the visually significant changes observed in this disease at the level of the photoreceptors [ Figure 1a ]. These transient retinal changes specifically occur at the level of the inner segment ellipsoid and outer segment/retinal pigment epithelium line.…”