Faculty Bibliography

Purpose: Drusenoid pigment epithelial detachments (PEDs) are a defined path to atrophy in age-related macular degeneration (AMD). We analyzed the relationships between retinal pigment epithelium (RPE) and drusen volume changes during the PED lifecycle, using spectral-domain optical coherence tomography (SD-OCT). Methods: Twenty-one cases of drusenoid PED tracked using SD-OCT through periods of growth and collapse were evaluated. Volumetric calculations and piece-wise linear regression analysis were used to determine the breakpoint between growth and collapse. Spectral-domain OCT scans were independently evaluated for the appearance of intraretinal hyperreflective foci, acquired vitelliform lesions (AVLs), and disruptions to the RPE+basal lamina band. Timing of these events with respect to the breakpoint was statistically evaluated. Morphometric characteristics of drusenoid PEDs were correlated with rate of PED collapse and final visual acuity. Results: Mean age of subjects was 75.3 years and mean period of follow up was 4.1 years (median 4.5 years; range, 0.6-6.6 years). The lifecycle of drusenoid PEDs was asymmetric, in that the rate of collapse (0.199 mm3/month) is significantly faster (P < 0.001) than the rate of growth (0.022 mm3/month). Appearance of intraretinal hyperreflective foci and AVLs preceded the breakpoint (both P < 0.001). The timing of disruptions to the RPE+basal lamina band did not differ from the breakpoint (P = 0.510). Maximal height, volume, and diameter of drusenoid PEDs were inversely correlated with final visual acuity (all P < 0.001) and positively correlated with the rate of PED collapse (all P < 0.001). Conclusions: Spectral-domain OCT signatures, plausibly attributable to anteriorly migrated RPE and disintegration of the RPE layer, precede or occur simultaneously with changes in volume of drusenoid PED during the lifecycle of this lesion.

Purpose: We used fractal dimensional analysis to analyze retinal vascular disease burden in eyes with diabetic retinopathy using spectral-domain optical coherence tomography angiography (OCTA). Methods: A retrospective study was performed of 13 eyes with diabetic retinopathy without diabetic macular edema and 56 control eyes. Optical coherence tomography angiography images were acquired using the RTVue XR Avanti. Automated segmentation was obtained through the superficial and deep capillary plexuses for each eye. Grayscale OCTA images were standardized and binarized using ImageJ. Fractal box-counting analyses were performed using Fractalyse. Fractal dimensions (FD) as well as software-generated vascular density analyses of the superficial and deep capillary plexuses were compared between diabetic and control eyes using 2-tailed t-tests and 1-way multivariate ANOVA (MANOVA) analyses. Results: The superficial and deep plexuses from diabetic and control eyes were analyzed. The average FD for diabetic eyes was significantly lower than control eyes for the superficial (P = 4.513 x 10-3) and deep (P = 2.653 x 10-3) capillary plexuses. In diabetic eyes, the vascular density also was significantly reduced in the superficial (P = 8.068 x 10-5) and deep (P = 3.120 x 10-6) capillary plexuses. One-way MANOVA showed a significant difference between diabetic and control eyes. Conclusions: The OCTA FD is significantly reduced in the superficial and deep capillary plexuses in eyes with diabetic retinopathy. Applying fractal analysis to OCTA imaging holds the potential to establish quantitative parameters for microvascular pathology.

PURPOSE: The range of subretinal hyperreflective material (SHRM) seen in macular disease includes type 2 macular neovascularization, fibrosis, exudation, vitelliform material and hemorrhage. The prognostic significance of SHRM has been evaluated retrospectively in clinical trials but discriminating SHRM subtypes traditionally requires multiple imaging modalities. The purpose of this study is to describe optical coherence tomography angiography (OCTA) flow characteristics and artifacts which might help to distinguish SHRM subtypes. DESIGN: Validity analysis. METHODS: Patients with age-related macular degeneration (AMD), myopia, pachychoroid disease and macular dystrophy, manifesting SHRM on optical coherence tomography (OCT), were recruited. Clinical chart review and multimodal imaging established the SHRM subtype. All patients underwent OCTA (RTVue XR, Optovue). OCT and OCTA images were examined together for i) intrinsic flow, ii) retinal projection onto the anterior SHRM surface (strong, weak, absent), iii) retinal projection through SHRM onto retinal pigment epithelium (RPE), iv) masking of choriocapillaris flow. RESULTS: Thirty-three eyes of 25 patients were included (type 2 neovascularizationx3; fibrosisx4; exudationx10; hemorrhagex5; vitelliformx17). Mean age per eye was 76 years (SD: 12). Intrinsic flow was strongest in type 2 neovascularization. Subretinal fibrosis showed limited flow in residual large caliber vessels and branches. Flow was not detected within foci of exudation, hemorrhage or vitelliform lesions. Retina-SHRM surface projection was strongest onto smooth surfaced SHRM and weaker onto exudation. Retinal projection was weakest on the surface of vitelliform lesions. Retina-RPE projection was masked by dense hemorrhage and vitelliform material. In compound SHRM, OCTA distinguished between vascular and avascular components. CONCLUSION: Optical coherence tomography angiography can distinguish vascular from avascular SHRM components. OCTA artifacts may distinguish certain avascular SHRM components.

Acute macular neuroretinopathy (AMN) is a relatively rare condition originally defined by the presence of intraretinal, reddish-brown, wedge-shaped lesions, the apices of which tend to point towards the fovea. Acute onset of paracentral scotomas corresponding to the clinically evident lesions is both common and characteristic. While the pathogenesis of AMN is complex, recent research suggests a microvascular etiology. Advances in multimodal imaging have enabled better characterization of this retinal disorder and have led to newly proposed diagnostic criteria. We review 101 reported cases in the English and non-English language literature identified from 1975, when AMN was first described, to December, 2014. We discuss common risk factors, demographic and clinical characteristics, and multimodal imaging findings, which together provide insights into pathogenesis and guide areas of future investigation.

PURPOSE: To determine the sensitivity of the combination of optical coherence tomography angiography (OCTA) and structural optical coherence tomography (OCT) for detecting type 1 neovascularization (NV) and to determine significant factors that preclude visualization of type 1 NV using OCTA. METHODS: Multicenter, retrospective cohort study of 115 eyes from 100 patients with type 1 NV. A retrospective review of fluorescein (FA), OCT, and OCTA imaging was performed on a consecutive series of eyes with type 1 NV from five institutions. Unmasked graders utilized FA and structural OCT data to determine the diagnosis of type 1 NV. Masked graders evaluated FA data alone, en face OCTA data alone and combined en face OCTA and structural OCT data to determine the presence of type 1 NV. Sensitivity analyses were performed using combined FA and OCT data as the reference standard. RESULTS: A total of 105 eyes were diagnosed with type 1 NV using the reference. Of these, 90 (85.7%) could be detected using en face OCTA and structural OCT. The sensitivities of FA data alone and en face OCTA data alone for visualizing type 1 NV were the same (66.7%). Significant factors that precluded visualization of NV using en face OCTA included the height of pigment epithelial detachment, low signal strength, and treatment-naive disease (P < 0.05, respectively). CONCLUSIONS: En face OCTA and structural OCT showed better detection of type 1 NV than either FA alone or en face OCTA alone. Combining en face OCTA and structural OCT information may therefore be a useful way to noninvasively diagnose and monitor the treatment of type 1 NV.

PURPOSE: To define the phenotypic characteristics of the bullous variant of central serous chorioretinopathy (CSC) using multimethod imaging. DESIGN: Retrospective, observational case series. PARTICIPANTS: Twenty-one eyes of 14 patients with bullous retinal detachment resulting from CSC (bullous CSC group) and 122 eyes of 84 patients with chronic CSC without bullous retinal detachment (nonbullous CSC group). METHODS: We performed a retrospective review of clinical and multimethod imaging data of patients who sought treatment from the authors with bullous retinal detachment resulting from CSC between January 2010 and November 2015. Multimethod imaging comprised color photography, fluorescein angiography, fundus autofluorescence, and high-resolution optical coherence tomography. Consecutive cases of chronic CSC without bullous retinal detachment, seen during the same period, comprised a comparative group. MAIN OUTCOME MEASURES: Qualitative and quantitative characteristics of the choroid, retinal pigment epithelium, and retina were compared between the 2 groups. RESULTS: Mean age of the bullous CSC group was 53.8 years. There was no difference in age, visual acuity, corticosteroid use, or the proportion of white patients and men between the 2 groups (all P > 0.132). Peripheral nonperfusion occurred only in eyes with bullous retinal detachment (38% of cases). Retinal pigment epithelial tears were seen in 95% of eyes in the bullous group and none of the eyes in the nonbullous CSC group. The bullous CSC group demonstrated a greater number of pigment epithelial detachments (PEDs) and more eyes demonstrated PEDs with internal hyperreflectivity (both P < 0.016). Mean subfoveal choroidal thickness in the bullous CSC group (463.1+/-83.1 mum) was not different compared with that of the nonbullous CSC group (400.6+/-100.6 mum; P = 0.993). More eyes in the bullous CSC group demonstrated hyperreflectivity around large choroidal vessels and at the level of the choriocapillaris on OCT (P < 0.001). Retinal folds and subretinal fibrin were identified in a greater proportion of eyes in the bullous CSC group (both P < 0.001). CONCLUSIONS: Bullous retinal detachment is a rare manifestation of chronic CSC and is characterized by a unique constellation of phenotypic and multimethod imaging features.