Faculty Bibliography

PURPOSE: To describe the multimodal imaging findings of transient subretinal deposits occurring in multiple evanescent white dot syndrome (MEWDS). METHODS: The multimodal imaging characteristics of transient subretinal deposits occurring in MEWDS were investigated with ultra-widefield color and fundus autofluorescence, cross-sectional and en-face optical coherence tomography (OCT), en face OCT-angiography, and quantitative autofluorescence. RESULTS: A 28-year-old woman presented with photopsia and temporal visual field loss in her right eye. Her best-corrected visual acuity was 20/20 in her right eye and 20/25 in her left eye. Funduscopic examination showed characteristic peripapillary hyperautofluorescent white dots of MEWDS corresponding to ellipsoid zone disruption on OCT. These lesions became confluent throughout the posterior fundus over the next 4 weeks. As the patient's symptoms were resolving, a second type of transient hyperautofluorescent lesion was noted which corresponded to hyperreflective subretinal deposits on cross-sectional and en face structural OCT. These subretinal deposits were most evident at 10-week follow-up and had nearly resolved at 14-week follow-up. Quantitative autofluorescence showed that, unlike the acute MEWDS lesions, the hyperautoflurescence of the subretinal deposits persisted after photobleaching. At multiple time points over 14 weeks of follow-up, OCT angiography showed no evidence of retinal or choroidal flow abnormalities. CONCLUSION: Transient subretinal deposits may develop during MEWDS in areas of previous diffuse outer retinal disruption. As these deposits remain hyperautoflurescent on quantitative autofluorescence after photobleaching, they may represent accumulations of debris originating from damaged photoreceptor outer segments.

PURPOSE: To report a case of "posterior scleral melanocytosis," a pigmented lesion of the posterior sclera that clinically resembles a flat choroidal nevus. METHODS: Case report of a patient with posterior scleral melanocytosis. Multimodal imaging, including swept source optical coherence tomography, was used to demonstrate the scleral location of the pigmented lesion and to distinguish its features from a typical choroidal nevus present in the same eye. RESULTS: An 86-year-old woman was seen for regular follow-up for neovascular age-related macular degeneration in her right eye and 2 pigmented lesions in her left eye, both presumed to be choroidal nevi. Anterior segment examination showed no evidence of ocular or dermal melanocytosis. Optical coherence tomography of the pigmented lesion in the left eye showed two distinct patterns. One lesion showed hyperreflectivity within the choroidal tissue associated with posterior shadowing, whereas the second lesion showed normal choroidal reflectivity with hyperreflectivity confined to the inner sclera associated with marked posterior shadowing. CONCLUSION: To the authors' knowledge, this is the first report of posterior scleral melanocytosis, a pigmented fundus lesion confined to the inner sclera. The need for high-penetrance optical coherence tomography to differentiate these lesions from a typical choroidal nevus may explain why this entity has not been previously described. The true nature of this entity will ultimately require histopathologic study.

Drusen are lipid-, mineral-, and protein-containing extracellular deposits that accumulate between the basal lamina of the retinal pigment epithelium (RPE) and Bruch's membrane (BrM) of the human eye. They are a defining feature of age-related macular degeneration (AMD), a common sight-threatening disease of older adults. The appearance of heterogeneous internal reflectivity within drusen (HIRD) on optical coherence tomography (OCT) images has been suggested to indicate an increased risk of progression to advanced AMD. Here, in a cohort of patients with AMD and drusen, we show that HIRD indicated an increased risk of developing advanced AMD within 1 year. Using multimodal imaging in an independent cohort, we demonstrate that progression to AMD was associated with increasing degeneration of the RPE overlying HIRD. Morphological analysis of clinically imaged cadaveric human eye samples revealed that HIRD was formed by multilobular nodules. Nanoanalytical methods showed that nodules were composed of hydroxyapatite and that they differed from spherules and BrM plaques, other refractile features also found in the retinas of patients with AMD. These findings suggest that hydroxyapatite nodules may be indicators of progression to advanced AMD and that using multimodal clinical imaging to determine the composition of macular calcifications may help to direct therapeutic strategies and outcome measures in AMD.

Importance/UNASSIGNED:Analysis of collateral vessel formation following retinal vein occlusion may advance our understanding of the venous outflow anatomy in the macula. Objective/UNASSIGNED:To determine the location of collateral vessels with optical coherence tomography (OCT) angiography imaging. Design, Setting, and Participants/UNASSIGNED:Observational retrospective cohort study. Collateral vessel formation was studied with OCT angiography (OCTA) in patients with retinal vein occlusion (RVO). The study took place at 2 retinal practices (Vitreous Retina Macula Consultants of New York and Stein Eye Institute, University of California, Los Angeles), with patient records retrieved from March 2015 to August 2017. Data analysis was completed in November 2017. Exposures/UNASSIGNED:Collaterals identified with fundus photography and/or fluorescein angiography were analyzed with OCTA to determine their course through the superficial vascular plexus (SVP) and the deep vascular complex (DVC). Main Outcomes and Measures/UNASSIGNED:Collateral vessel pathways through the SVP and DVC were analyzed with cross-sectional and en face OCT and OCTA segmentation and color-coded volume renderings prepared from raw OCTA voxel data. Results/UNASSIGNED:From 23 eyes (22 branch and 1 hemispheric retinal vein occlusion ) of 23 patients (mean [SD] age, 73 [11] years), 101 collateral vessels were identified and analyzed (mean [SD], 4.4 [2.0]; range, 2-9 collateral per eye). On OCTA, the collaterals appeared as curvilinear dilated flow signals that connected veins across the horizontal raphe or veins on opposite sides of an occluded venous segment within the same retinal hemisphere. Of the 101 collaterals analyzed, all showed greater flow signal in the DVC, and all had some portion of their course identified within the DVC. No collaterals were found exclusively in the SVP. Volume renderings for 3 cases confirmed qualitatively that retinal collateral vessels course through the retina predominantly at the level of the DVC. Conclusions and Relevance/UNASSIGNED:Based on a limited number of cases, all collateral vessels associated with retinal vein occlusion were found to course through the DVC. The absence of collaterals isolated to the SVP supports a serial arrangement of the SVP and DVC, with venous drainage predominantly coursing through the DVC.

The recent introduction of optical coherence tomography angiography (OCTA) has remarkably expanded our knowledge of the choroid through in vivo investigation of the anatomical and pathological features of this important vascular layer. New insights elucidating the morphological features of the choroid, in both physiological and pathological conditions, indicate that this vascular structure plays a crucial role in many chorioretinal disorders. In this article, a review of the salient histological and anatomical features of the choroid, essential for the proper interpretation of in vivo imaging, is followed by a discussion of the fundamental principles of OCTA and the application of this advanced imaging modality to study and understand the choroid. The current limitations of OCTA and potential advancements that may improve the widespread adoption of this tool are also discussed. A detailed review of the OCTA features of the choroid in the healthy eye is followed by relevant findings in major chorioretinal diseases, including age-related macular degeneration, central serous chorioretinopathy, uveitis, and inherited retinal disorders.