Faculty Bibliography

PURPOSE:To perform an unsupervised machine learning clustering of patients with punctate inner choroidopathy (PIC) and provide new insights into the significance of pachychoroid disease features in PIC eyes. METHODS:Retrospective multicenter study, including 102 eyes from 82 patients diagnosed with PIC. Demographics, clinical data, and multimodal imaging, including fundus photography, optical coherence tomography, and indocyanine green angiography, were collected. Clusters of eyes were identified, and multilevel logistic regression analysis was performed to compare between-group differences. RESULTS:Using 17 clinical features, two distinct clusters of patients with PIC were identified. Cluster 1 patients were characterized by older age, high myopia, myopic maculopathy features, thin choroids, multiple lesions, and a higher likelihood of developing patchy chorioretinal atrophy. Cluster 2 consisted of younger age, emmetropia or low myopia, thick choroids, choroidal vascular hyperpermeability on late-phase indocyanine green angiography, and high prevalence of focal choroidal excavation. These features exhibited significant differences ( P < 0.05) between the two clusters. CONCLUSION:While PIC typically affects young myopic female patients with thin choroids, a subset of patients with PIC exhibits features associated with pachychoroid disease. Considering the potential influence of choroidal venous insufficiency on PIC manifestations and secondary complications, we propose the term "punctate inner pachychoroidopathy" to characterize this distinct subtype of PIC.

PURPOSE:To investigate alterations in macular perfusion variability due to branch retinal vein occlusion (BRVO) using a novel approach based on optical coherence tomography angiography (OCTA) coefficient of variation (CoV) analysis. METHODS:Thirteen eyes of 13 patients with macular ischemia due to BRVO were studied. Multiple consecutive en face OCTA images were acquired. Bias field correction, spatial alignment, and normalization of intensities across the images were performed followed by pixelwise computation of standard deviation divided by the mean to generate a CoV map. Region of interest-based CoV values, derived from this map, for arterioles, venules, and the microvasculature were compared between regions with macular ischemia and control areas of the same eye. Control areas were regions of the same macula that were not affected by the BRVO and had normal retinal vascular structure as seen on multimodal imaging and normal retinal vascular density measurements as quantified using OCTA. RESULTS:CoV increased by a mean value of 17.6% within the microvasculature of ischemic regions compared to the control microvasculature (P < 0.0001). CoV measurements of microvasculature were consistently greater in the ischemic area of all 13 eyes compared to control. There were no differences in CoV measurements between ischemic and control areas for arterioles (P = 0.13) and venules (P = 1.0). CONCLUSIONS:Greater variability in microvasculature perfusion occurs at sites of macular ischemia due to BRVO. We report a novel way for quantifying macular perfusion variability using OCTA. This technique may have applicability for studying the pathophysiology of other retinal vascular diseases.

BACKGROUND:Imaging indicators of macular neovascularization risk can help determine patient eligibility for new treatments for geographic atrophy secondary to age-related macular degeneration. Because type 1 macular neovascularization includes inflammation, we assessed by histology the distribution of cells with inflammatory potential in two fellow eyes with age-related macular degeneration. METHODS:Two eyes of a White woman in her 90's with type 3 macular neovascularization treated with antivascular endothelial growth factor were prepared for high-resolution histology. Eye-tracked spectral domain optical coherence tomography applied to the preserved donor eyes linked in vivo imaging to histology. Cells were enumerated in the intraretinal, subretinal, and subretinal retinal pigment epithelium (RPE)-basal lamina compartments on 199 glass slides. Cells with numerous organelles were considered to RPE-derived; cells with sparse RPE organelles were considered non-RPE phagocytes. RESULTS:Both eyes had soft drusen and abundant subretinal drusenoid deposit. In the retina and subretinal space, RPE-derived cells, including hyperreflective foci, were common (n = 125 and 73, respectively). Non-RPE phagocytes were infrequent (n = 5 in both). Over drusen, RPE morphology transitioned smoothly from the age-normal layer toward the top, suggesting transdifferentiation. The sub-RPE-basal lamina space had RPE-derived cells (n = 87) and non-RPE phagocytes (n = 49), including macrophages and giant cells. CONCLUSION:Numerous sub-RPE-basal lamina cells of several types are consistent with the documented presence of proinflammatory lipids in drusen and aged Bruch's membrane. The relatively compartmentalized abundance of infiltrating cells suggests that drusen contents are more inflammatory than subretinal drusenoid deposit, perhaps reflecting their environments. Ectopic RPE occurs frequently. Some manifest as hyperreflective foci. More cells may be visible as optical coherence tomography technologies evolve.

PURPOSE/UNASSIGNED:Fluid presence and dynamism is central to the diagnosis and management of neovascular age-related macular degeneration. On optical coherence tomography (OCT), some hyporeflective spaces arise through vascular permeability (exudation) and others arise through degeneration (transudation). Herein we determined whether the histological appearance of fluid manifested this heterogeneity. METHODS/UNASSIGNED:Two eyes of a White woman in her 90s with anti-vascular endothelial growth factor treated bilateral type 3 neovascularization secondary to age-related macular degeneration were osmicated, prepared for submicrometer epoxy resin sections, and correlated to eye-tracked spectral domain OCT. Examples of intraretinal tissue fluid were sought among similarly prepared donor eyes with fibrovascular scars, in a web-based age-related macular degeneration histopathology resource. Fluid stain intensity was quantified in reference to Bruch's membrane and the empty glass slide. RESULTS/UNASSIGNED:Exudative fluid by OCT was slightly reflective and dynamically responded to anti-vascular endothelial growth factor. On histology, this fluid stained moderately, possessed a smooth and homogenous texture, and contained blood cells and fibrin. Nonexudative fluid in degenerative cysts and in outer retinal tubulation was minimally reflective on OCT and did not respond to anti-vascular endothelial growth factor. By histology, this fluid stained lightly, possessed a finely granular texture, and contained mainly tissue debris. Quantification supported the qualitative impressions of fluid stain density. Cells containing retinal pigment epithelium organelles localized to both fluid types. CONCLUSIONS/UNASSIGNED:High-resolution histology of osmicated tissue can distinguish between exudative and nonexudative fluid, some of which is transudative. TRANSLATIONAL RELEVANCE/UNASSIGNED:OCT and histological features of different fluid types can inform clinical decision-making and assist in the interpretation of newly available automated fluid detection algorithms.

PURPOSE/OBJECTIVE:To enable in vivo analysis of drusen composition and lifecycle, we assessed macular nodular and cuticular drusen using histology. METHODS:Median and interquartile range (IQR) of base widths of single (non-confluent) nodular drusen in 3 sources were determined histologically: 43 eyes of 43 clinically undocumented donors, in an online resource; one eye with punctate hyperfluorescence in fluorescein angiography (FA); and two eyes of one patient with bilateral "starry sky" cuticular drusen. All tissues were processed for high-resolution epoxy-resin histology and for cuticular drusen, transmission electron microscopy. RESULTS:All drusen localized between the retinal pigment epithelium basal lamina and inner collagenous layer of Bruch's membrane. They were solid, globular, homogeneously stained with toluidine blue, and uncovered by basal laminar deposit and basal mounds. Median base widths were 13.0 µm (Source 1, N=128 drusen, IQR 7.7, 20.0 µm), 15.3 µm (Source 2, N=87, IQR 10.6, 20.5 µm), and 7.3 µm (Source 3, N=78, IQR 3.9, 14.1 µm). CONCLUSIONS:In three samples, >90% of solitary nodular drusen were <30 µm, the visibility threshold in color fundus photography; these drusen are hyperfluorescent in FA. Whether these progress to soft drusen, known as high-risk from epidemiology studies and hypofluorescent, may be determinable from multimodal imaging datasets that include FA.

PURPOSE/OBJECTIVE:Clinicopathologic correlation of two optical coherence tomography (OCT) features in neovascular age-related macular degeneration. METHODS:Case report, clinicopathologic correlation. RESULTS:A patient in her 90s was diagnosed with Type 3 macular neovascularization secondary to age-related macular degeneration in the index right eye and underwent intravitreal antivascular endothelial growth factor treatment for 5 years. A double-layer sign on in vivo OCT was correlated to calcified drusen on histology. Furthermore, hyperfluorescence on fluorescein angiography corresponded on histology to choroidal hypertransmission on OCT and retinal pigment epithelium atrophy above calcified drusen. CONCLUSION/CONCLUSIONS:A double-layer sign on OCT can represent nonneovascular subretinal pigment epithelium material including wide and flat calcific nodules. Furthermore, hyperfluorescence on FA, among different origins, can be due to a window defect corresponding to retinal pigment epithelium atrophy, which can be confirmed with OCT. Clinicopathological correlation using high-resolution histology can demonstrate the fine details available to clinical decision making through currently available in vivo OCT imaging.

PURPOSE/OBJECTIVE:To describe the clinical and multimodal imaging features of stellate multiform amelanotic choroidopathy (SMACH; also known as serous maculopathy due to aspecific choroidopathy). METHODS:Retrospective observational case series of eyes presenting with SMACH. Multimodal imaging including fundus photography, optical coherence tomography (OCT), OCT-angiography (OCTA), and indocyanine green angiography (ICGA) was analyzed. RESULTS:Eighteen eyes from 18 patients (mean age: 28±19 years) were included. The mean follow-up duration was 9 years. Ophthalmoscopy showed a yellowish-orange, dendriform choroidal lesion. At presentation, subretinal fluid (SRF) was seen in 10/18 cases (56%). Eight patients (44%) showed no evidence of SRF during a mean follow-up of 6 years. Cross-sectional OCT showed hyperreflective fibrous-like changes within the inner choroid with choriocapillaris flow preservation on OCTA. En face OCT showed a hyperreflective choroidal lesion with finger-like projections oriented in a stellate configuration. On ICGA, SMACH showed early and late hypofluorescence. None of the cases showed lesion growth. CONCLUSIONS:SMACH appears to be a unilateral choroidopathy characterized by distinctive multimodal imaging features. As SRF was absent in some cases, while a dendriform pattern was a consistent finding in all eyes, we propose renaming this entity "stellate multiform amelanotic choroidopathy", a name which retains its prior abbreviation "SMACH".

During the past 15 years, new treatment paradigms for neovascular age-related macular degeneration (nvAMD) have evolved due to the advent of intravitreal anti-vascular endothelial growth factor (VEGF) therapy and rapid advances in retinal imaging. Recent publications describe eyes with type 1 macular neovascularization (MNV) as showing more resistance to macular atrophy than eyes with other lesion types. We sought to explore whether the perfusion status of the native choriocapillaris (CC) surrounding type 1 MNV influences its pattern of growth. To evaluate this effect, we analyzed a case series of 22 eyes from 19 nvAMD patients with type 1 MNV exhibiting growth on swept-source optical coherence tomography angiography (SS-OCTA) over a minimum follow-up of 12 months. We observed an overall weak correlation between type 1 MNV growth and CC flow deficits (FDs) average size (τ = 0.17, 95% CI [- 0.20, 0.62]) and a moderate correlation with CC FD % (τ = 0.21, 95% CI [- 0.16, 0.68]). Type 1 MNV was located beneath the fovea in most of the eyes (86%) and median visual acuity was 20/35 Snellen equivalent. Our results support that type 1 MNV recapitulates areas of CC blood flow impairment while serving to preserve foveal function.

A progression sequence for age-related macular degeneration (AMD) learned from optical coherence tomography (OCT)-based multimodal (MMI) clinical imaging could add prognostic value to laboratory findings. In this work, ex vivo OCT and MMI were applied to human donor eyes prior to retinal tissue sectioning. The eyes were recovered from non-diabetic white donors aged ≥80 years old, with a death-to-preservation time (DtoP) of ≤6 h. The globes were recovered on-site, scored with an 18 mm trephine to facilitate cornea removal, and immersed in buffered 4% paraformaldehyde. Color fundus images were acquired after anterior segment removal with a dissecting scope and an SLR camera using trans-, epi-, and flash illumination at three magnifications. The globes were placed in a buffer within a custom-designed chamber with a 60 diopter lens. They were imaged with spectral domain OCT (30° macula cube, 30 µm spacing, averaging = 25), near-infrared reflectance, 488 nm autofluorescence, and 787 nm autofluorescence. The AMD eyes showed a change in the retinal pigment epithelium (RPE), with drusen or subretinal drusenoid deposits (SDDs), with or without neovascularization, and without evidence of other causes. Between June 2016 and September 2017, 94 right eyes and 90 left eyes were recovered (DtoP: 3.9 ± 1.0 h). Of the 184 eyes, 40.2% had AMD, including early intermediate (22.8%), atrophic (7.6%), and neovascular (9.8%) AMD, and 39.7% had unremarkable maculas. Drusen, SDDs, hyper-reflective foci, atrophy, and fibrovascular scars were identified using OCT. Artifacts included tissue opacification, detachments (bacillary, retinal, RPE, choroidal), foveal cystic change, an undulating RPE, and mechanical damage. To guide the cryo-sectioning, OCT volumes were used to find the fovea and optic nerve head landmarks and specific pathologies. The ex vivo volumes were registered with the in vivo volumes by selecting the reference function for eye tracking. The ex vivo visibility of the pathology seen in vivo depends on the preservation quality. Within 16 months, 75 rapid DtoP donor eyes at all stages of AMD were recovered and staged using clinical MMI methods.