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Purpose: Correlations between low luminance visual acuity deficits (LLVADs) and central choriocapillaris perfusion deficits were investigated to help explain how increases in LLVAD scores at baseline predict annual growth rates of geographic atrophy (GA)., Design: Prospective cross-sectional study., Methods: Photopic luminance best-corrected visual acuity (PL-BCVA) and low luminance BCVA (LL-BCVA) were measured using the Early Treatment Diabetic Retinopathy Study chart. LL-BCVA was measured using a 2.0-log unit neutral density filter. LLVADs were calculated as the difference between PL-BCVA and LL-BCVA. Within a fovea-centered 1-mm circle, the percentage of choriocapillaris flow deficits (CC FD%), drusen volume, optical attenuation coefficient (OAC) elevation volume, and outer retinal layer (ORL) thickness were assessed., Results: In all 90 eyes (30 normal eyes; 31 drusen-only eyes; 29 non-foveal GA eyes), significant correlations were found between the central CC FD% and PL-BCVA (r = -0.393, P < .001), LL-BCVA (r = -0.534, P < .001), and the LLVAD (r = 0.439, P < .001). Central cube root (cubrt) drusen volume, cubrt OAC elevation volume, and ORL thickness were correlated with PL-BCVA, LL-BCVA, and LLVADs (all P < .05). Stepwise regression models showed that central cubrt OAC elevation volume and ORL thickness were associated with PL-BCVA (R 2  = 0.24, P < .05); central CC FD%, cubrt OAC elevation volume, and ORL thickness were associated with LL-BCVA (R 2  = 0.44, P < .01); and central CC FD% and ORL thickness were associated with LLVAD (R 2  = 0.24, P < .01)., Conclusions: The significant correlations between central CC FD% and LLVAD support the hypothesis that the ability of LLVAD to predict the growth of GA is mediated through a decrease in macular choriocapillaris perfusion., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: To determine whether the outer retinal layer (ORL) thickness around geographic atrophy (GA) could serve as a clinical biomarker to predict the annual enlargement rate (ER) of GA., Design: Retrospective analysis of a prospective, observational case series., Methods: Eyes with GA were imaged with a swept-source OCT 6 × 6 mm scan pattern. GA lesions were measured from customized en face OCT images and the annual ERs were calculated. The ORL was defined and segmented from the inner boundary of outer plexiform layer (OPL) to the inner boundary of retinal pigment epithelium (RPE) layer. The ORL thickness was measured at different subregions around GA., Results: A total of 38 eyes from 27 participants were included. The same eyes were used for the choriocapillaris (CC) flow deficit (FD) analysis and the RPE to the Bruch membrane (RPE-BM) distance measurements. A negative correlation was observed between the ORL thickness and the GA growth. The ORL thickness in a 300-μm rim around GA showed the strongest correlation with the GA growth (r = -0.457, P = .004). No correlations were found between the ORL thickness and the CC FDs; however, a significant correlation was found between the ORL thickness and the RPE-BM distances around GA (r = -0.398, P = .013)., Conclusions: ORL thickness showed a significant negative correlation with annual GA growth, but also showed a significant correlation with the RPE-BM distances, suggesting that they were dependently correlated with GA growth. This finding suggests that the loss of photoreceptors was associated with the formation of basal laminar deposits around GA., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: The retinal pigment epithelium (RPE) to Bruch membrane (BM) distance around geographic atrophy (GA) was measured using an optical attenuation coefficient (OAC) algorithm to determine whether this measurement could serve as a clinical biomarker to predict the annual square root enlargement rate (ER) of GA., Design: A retrospective analysis of a prospective, observational case series., Methods: Eyes with GA secondary to age-related macular degeneration (AMD) were imaged with swept-source OCT (SS-OCT) using a 6 × 6-mm scan pattern. GA lesions were identified and measured using customized en face OCT images, and GA annual square root ERs were calculated. At baseline, the OACs were calculated from OCT datasets to generate customized en face OAC images for GA visualization. RPE-BM distances were measured using OAC data from different subregions around the GA., Results: A total of 38 eyes from 27 patients were included in this study. Measured RPE-BM distances were the highest in the region closest to GA. The RPE-BM distances immediately around the GA were significantly correlated with GA annual square root ERs (r = 0.595, P < .001 for a 0- to 300-µm rim around the GA). No correlations were found between RPE-BM distances and previously published choriocapillaris (CC) flow deficits in any subregions., Conclusions: RPE-BM distances from regions around the GA significantly correlate with the annual ERs of GA. These results suggest that an abnormally thickened RPE/BM complex contributes to GA growth and that this effect is independent of CC perfusion deficits., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: Correlations among enlargement rates (ERs) of geographic atrophy (GA) and choriocapillaris (CC) flow deficits (FDs), mean choroidal thickness (MCT), and choroidal vascularity index (CVI) were investigated using swept source-optical coherence tomography (SS-OCT) in age-related macular degeneration (AMD)., Design: A retrospective review of prospective, observational case series., Methods: Eyes with GA from AMD were imaged with SS-OCT using 6 × 6-mm scan pattern. GA lesions were identified and measured using customized en face structural images, and annual square root ERs of GA were calculated. At baseline, choriocapillaris FDs from different regions outside the GA were measured, and MCT and CVI from the entire scan area were measured. All measurements were performed using previously published and validated algorithms., Results: A total of 38 eyes from 27 patients were included. The CC FDs within each region around GA lesions were highly correlated with ERs of GA (all P < .005). CVI inside the GA region was correlated with the ERs (P = .03), whereas other choroidal measurements had no significant correlation with the ERs of GA (P > .06)., Conclusions: Statistically significant correlations were found between the ERs of GA and CC percentage of FD (FD%) from the entire scan region outside the GA and not just the region immediately adjacent to the GA. These results suggest that abnormal CC perfusion throughout the macula contributes to disease progression in eyes with GA. CVI inside the GA region could also be a potential indicator for the growth of GA., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: A compensation strategy that was developed to measure the choriocapillaris (CC) flow deficits (FDs) under drusen was tested in eyes with large drusen from age-related macular degeneration (AMD) before and after the drusen spontaneously resolved without evidence of disease progression., Design: Prospective, observational consecutive case series., Methods: Patients with AMD were enrolled in a prospective swept-source optical coherence tomography (SS-OCT) imaging study. Consecutive eyes with large drusen were followed, and eyes that underwent spontaneous collapse of drusen without evidence of disease progression were identified retrospectively. The drusen-resolved regions were manually outlined. CC FDs were measured using a previously published compensation strategy that adjusted for the decreased signal intensity underlying drusen. Both the percentage of FDs (FD%) and the mean FD sizes (MFDSs) were measured before and after drusen resolution., Results: Resolution of drusen was identified in 8 eyes from 8 patients. The average interval between the 2 visits was 7.8 months. The average drusen volumes measured between visits were 0.23 and 0.04 mm 3 , respectively. After the drusen resolved, the average follow-up time without evidence of disease progression was 10.1 months. When the 2 visits were compared, there were no statistically significant differences in any of the CC parameters within the drusen resolved regions once the compensation strategy was applied (all P values >.22)., Conclusions: In this naturally occurring experiment in which drusen collapsed without evidence of disease progression, the CC parameters were similar once our compensation strategy was applied both before and after the drusen resolved., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: Choriocapillaris (CC) imaging of normal eyes with swept-source optical coherence tomographic angiography (SS-OCTA) was performed, and the percentage of CC flow deficits (FD%) and the average area of CC flow deficits (FDa) were compared within the given macular regions., Design: A prospective, cross-sectional study., Methods: Subjects with normal eyes ranging in age from their 20s through their 80s were imaged with SS-OCTA (PLEX Elite 9000; Carl Zeiss Meditec, Dublin, California, USA) using both 3×3-mm and 6×6-mm macular scan patterns. The CC images were generated using a previously published and validated algorithm. In both 3×3-mm and 6×6-mm scans, the CC FD% and FDa were measured in circular regions centered on the fovea with diameters as 1 mm and 2.5 mm (C 1 and C 2.5 ). In 6×6-mm scans, the FD% and FDa were measured within an additional circular region with diameter as 5 mm (C 5 ). The correlations between FD% and FDa from each region were analyzed with Pearson correlation coefficients., Results: A total of 164 eyes were analyzed. There was excellent correlation between CC FDa and FD% measurements from each region. In the 3×3-mm scans, the correlations in the C 1 and C 2.5 regions were 0.83 and 0.90, respectively. In the 6×6-mm scans, the correlations in C 1 , C 2.5 , and C 5 regions were 0.90, 0.89, and 0.89, respectively., Conclusions: When measuring CC FDs, we found excellent correlations between FDa and FD% in regions from 3×3-mm and 6×6-mm scans. Further studies are needed to determine if one parameter is more useful when studying diseased eyes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Swept source optical coherence tomography angiography (SS-OCTA) was used to study the prevalence, incidence, and natural history of subclinical macular neovascularization (MNV) in eyes with unilateral nonexudative age-related macular degeneration., Design: Prospective cohort study., Methods: Patients were imaged using 3- × 3-mm and 6- × 6-mm SS-OCTA scan patterns. MNV was detected using the outer retina to choriocapillaris en face slab. Prevalence and incidence of subclinical MNV, Kaplan-Meier cumulative estimates for the overall risk of exudation, and the association between neovascular lesion size and the risk of exudation were assessed through 2 years., Results: From August 2014 through March 2018, 227 patients (154 intermediate and 73 late age-related macular degeneration eyes) underwent SS-OCTA imaging. Thirty eyes (13.2%) had subclinical MNV at first imaging and 12 eyes (8.9%) developed subclinical MNV during follow-up. Of the 191 eyes with >1 visit, 19 developed exudation. Fourteen of these eyes had pre-existing subclinical MNV. The incidence of exudation from the time of first detection of any subclinical MNV was 34.5%. The relative risk of exudation after detection of subclinical MNV was 13.6 times greater (95% confidence interval 4.9-37.7) than in the absence of subclinical MNV (P < .001). There was no significant risk of exudation based on lesion size alone (P = .91)., Conclusions: By 24 months, the risk of exudation was 13.6 times greater for eyes with subclinical MNV detected by SS-OCTA compared with eyes without subclinical MNV. For eyes with subclinical MNV in the absence of symptomatic exudation, we recommend close follow-up without treatment., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: Swept-source optical coherence tomography angiography (SS-OCTA) was used to measure the age-dependent changes in macular choriocapillaris (CC) flow deficits (FDs) in normal eyes., Design: A prospective, cross-sectional study., Methods: Subjects with normal eyes ranging in age from their 20s to their 80s were imaged using a 100-kHz SS-OCTA instrument (PLEX Elite 9000, Carl Zeiss Meditec, Dublin, California, USA). Both 3 × 3-mm and 6 × 6-mm scans were used to image the macular CC. Visualization of the CC and quantification of FDs were performed using a previously validated algorithm. The percentage of FDs (FD%) in the central 1-mm circle (C 1 ), 1.5-mm rim (R 1.5 ), and 2.5-mm circle (C 2.5 ) from the 3 × 3-mm and 6 × 6-mm scans and FD% in the 2.5-mm rim (R 2.5 ) and 5-mm circle (C 5 ) from the 6 × 6-mm scans were measured and correlated with age and axial length., Results: A total of 164 subjects were enrolled, with at least 10 subjects from each decade of life. No meaningful correlations were found between FD% and axial length (|r| < 0.30). FD% in all fields increased with increasing age (all r > 0.50; all P < .001); however, the greatest increases were found in the central macula C 1 regions and the smallest increases in the peripheral macula R 2.5 regions., Conclusions: In normal aging, the FD% increased with age across the central 5 mm of the macula, but the greatest increase was found in the central 1-mm region of the macula., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: To investigate the involvement of the retinal and choriocapillaris microvasculature in intermediate uveitis on optical coherence tomography angiography (OCT-A)., Design: Case-control study., Methods: Patients and age-matched controls were imaged with swept-source OCT-A. Using ImageJ, superficial and deep retinal vasculature were semi-automatically analyzed for vessel (VD) and skeleton density (SD), vessel diameter index (VDI), and fractal dimension (FD). Choriocapillaris layer was automatically graded for mean signal intensity, signal intensity standard deviation, kurtosis of signal intensity distribution, and flow signal voids., Results: Twenty-nine intermediate uveitis eyes and 30 control eyes were included. Both superficial and deep retinal layers showed significant reduction in all OCT-A parameters (eg, superficial retinal layer: 0.31 vs 0.40 VD, 5.6e -8 vs 6.4e -8 SD, 5.4e 6 vs 6.1e 6 VDI, and 1.78 vs 1.79 FD, respectively, all P < .05). At the choriocapillaris layer a greater heterogeneity of perfusion with a shift toward a higher proportion of large confluent flow signal voids was present. Also in the absence of macular edema OCT-A parameters were reduced when compared with healthy controls (all parameters except for VDI in the superficial retinal layer and the choriocapillaris kurtosis and flow signal void analyses)., Conclusions: In intermediate uveitis, reduced vascular density and complexity in superficial as well as deep retinal layers and altered choriocapillaris perfusion are present. Moreover, these findings indicate impairment of the macular microvasculature even in the absence of macular edema. The results of our study may aid in the diagnosis as well as the monitoring of intermediate uveitis., (Copyright © 2018 Elsevier Inc. All rights reserved.)