PURPOSE:To compare non perfusion area (NPA) and the ischemic index (ISI) between 2 fields of view using ultra-widefield optical coherence tomography angiography (UWF-OCTA) and evaluate their correlation with diabetic retinopathy (DR) severity and predominantly peripheral lesions (PPL). DESIGN:Cross-sectional, retrospective study. PARTICIPANTS:Sixty-two patients (101 eyes) with DR without prior pan-photocoagulation (PRP) treatment, imaged with 12 × 12-mm and 21 × 26-mm scans on UWF-OCTA. Forty-nine patients (79 eyes) with same-day ultra-widefield color fundus photography (UWF-CFP) were included in the PPL analysis. METHODS:NPA was calculated from UWF-OCTA scans using a semi-automatic algorithm on FIJI. ISI was determined as NPA divided by total scan area. A subset of eyes with same-day UWF CFP were assessed by 2 graders for the presence and extent of fields with PPLs - defined as >50% of diabetic lesions in extended versus Early Treatment of Diabetic Retinopathy Study (ETDRS) fields. Eyes were classified as having PPLs if ≥ 1 field met this criterion. MAIN OUTCOME MEASURES:NPA and ISI from 12 × 12-mm and 21 × 26-mm scans and their association with DR severity. RESULTS:NPA and ISI were significantly greater in PDR versus NPDR for both scans and the NPA/ISI was significantly higher in the 21 × 26-mm scan (P < .001 for all). Both the 12 × 12-mm (OR: 1.26 [95% CI: 1.07-1.48, P = .006]) and the 21 × 26-mm ISI (OR: 1.20 [95% CI: 1.10-1.29, P < .001]) were significantly associated with increasing DR severity. ROC analysis showed similar performance between both scan ISI at predicting DR severity (AUC: 0.868 vs 0.878, P = .558). In the sub-analysis, presence of PPL was only significantly associated with ISI on the 21 × 26-mm scan (B = 0.43901, P = .009). However, the interaction of both presence (B = 0.16, P = .006) and extent (B = 0.2,5 P = .044) of PPLs with increasing DR severity was positively associated with increasing ISI on the 21 × 26-mm scan. CONCLUSIONS:NPA/ISI on both the 12 × 12-mm and 21 × 26-mm scans is predictive of DR severity, highlighting the importance of OCTA detection of ischemia. The wider scan area of the 21 × 26-mm scan can better assess far peripheral ischemia that correlates with PPLs, supporting its potential role in tracking DR progression.

Purpose:To investigate retinal microvascular and choriocapillaris changes across the newly proposed seven-step classification for macular telangiectasia type 2 (MacTel) using swept-source optical coherence tomography angiography (SS-OCTA). Methods:Cross-sectional, observational study including 111 eyes with MacTel (56 patients) and 120 matched control eyes (60 subjects). Participants underwent comprehensive ophthalmic examinations, including macular 6 × 6-mm SS-OCTA. MacTel eyes were categorized into one of seven grades (0-6) using multimodal imaging. SS-OCTA scans were processed to measure vessel density (VD), vessel skeletonized density (VSD), foveal avascular zone (FAZ) metrics, and choriocapillaris flow deficit percentage (CCFD%). Differences between groups were assessed using Mann-Whitney U, Kruskal-Wallis tests, and generalized mixed-effects models. Cluster analysis assessed the agreement between clinical grades and OCTA-based clusters. Results:Of the MacTel eyes, 32% were grade 0, 9% grade 1, 18% grade 2, 5% grade 3, 15% grade 4, 13% grade 5, and 8% grade 6. MacTel eyes exhibited significant alterations in VD and VSD, particularly in the central 1-mm circle and temporal/inferior sectors, alongside consistently higher CCFD% across all macular regions. Advanced grades (5-6) showed pronounced differences in VD, VSD, and CCFD% compared to early grades (0-2). Agreement between MacTel grading and OCTA-based clusters was fair to moderate (Adjusted Rand Index = 0.233), with higher concordance for grades 0 and 4 to 6. Conclusions:SS-OCTA reveals significant retinal vascular and choriocapillaris impairment in MacTel, with pronounced alterations in advanced disease grades. The observed vascular damage, extending beyond the MacTel area, underscores the value of OCTA in identifying disease severity and aiding in its classification.

PURPOSE:To explore associations among expanded field swept-source optical coherence tomography angiography metrics and the development of myocardial infarction, congestive heart failure (CHF), and all-cause mortality in diabetic patients with and without diabetic retinopathy (DR). METHODS:Baseline swept-source optical coherence tomography angiography images (6 × 6 mm, Montage 15 × 15 mm) were assessed for quantitative and qualitative metrics to identify parameters associated with myocardial infarction, CHF, and all-cause mortality. RESULTS:One hundred and seventy-eight eyes from 119 adults with diabetes without DR or with nonproliferative DR or proliferative DR were included (median 44 months, range 3-57 months). Eleven participants (9.2%) had a cardiovascular event (six myocardial infarction, five CHF) and seven (5.9%) died. Neovascularization vessel density (HR = 44.0, 95% confidence interval [CI]: 1.0-1,861.2, P = 0.048) and vitreous hemorrhage (HR = 39.7, 95% CI: 4.0-392.8, P = 0.002) were associated with CHF. Vitreous hemorrhage (HR = 13.5, 95% CI: 3.0-61.2, P = 0.001) and prior treatment with anti-vascular endothelial growth factor injections and panretinal photocoagulation (HR = 11.4, 95% CI: 2.0-66.3, P = 0.007) were associated with cardiovascular disease (CHF or myocardial infarction). Increased skeletonized vessel density of the deep capillary plexus (HR = 1.2, 95% CI: 1.0-1.5, P = 0.026) was associated with mortality. CONCLUSION:Neovascularization vessel density and skeletonized vessel density of the deep capillary plexus on swept-source optical coherence tomography angiography are associated with cardiovascular disease and mortality in patients with DR. These exploratory findings suggest that swept-source optical coherence tomography angiography may be a useful noninvasive tool to identify diabetic patients at increased risk of cardiovascular disease and death.

To investigate the longitudinal progression of non-perfusion areas (NPA) in treatment-naïve patients with diabetic retinopathy (DR) using swept-source OCT angiography (SS-OCTA), and to identify clinical and imaging predictors. Retrospective longitudinal study. At each visit, 6 × 6-mm and 12 × 12-mm SS-OCTA (PLEX® Elite 9000) macular scans were performed. NPA was measured using ImageJ. The ischemic index (ISI) was calculated as NPA divided by total scan area. ISI progression rate was quantified by the change from baseline to the last visit, normalized by time. Additional OCTA metrics, including vessel density and skeletonized vessel density, were calculated using the ARI Network. A total of 101 eyes from 70 DR patients were included, with a median age of 59 [52–68] years. During follow-up (median duration: 15.5 [6.0–27.0] months), ISI progression rate per year in the proliferative DR group (0.01 [-0.01-0,06]) is significantly faster than both mild non-proliferative DR (0.00 [0.00–0.00]) and moderate-severe non-proliferative DR (0.00 [0.00-0.02]) groups (all P < 0.05). Mixed-effects linear regression identified DR severity and baseline ISI as the only factors significantly associated with ISI progression rate, with beta values of 0.33 (95

To evaluate the predictive value of optical coherence tomography angiography (OCTA)-derived parameters for visual acuity (VA) decline in non-proliferative diabetic retinopathy (NPDR). In this retrospective longitudinal study, 102 eyes from 69 patients with NPDR were followed for a median of 30 months. All eyes underwent expanded field 6 × 6-mm and 12 × 12-mm swept-source OCTA centered on the fovea. Quantitative OCTA parameters including ischemia index (ISI), vessel density (VD), and perfusion density (PD) of the superficial (SCP), deep capillary plexus (DCP), and full retina were measured once at baseline. The primary outcomes were ≥ 5-letter and ≥ 10-letter loss in VA from baseline to final follow-up. Multilevel mixed-effects Cox regression models, adjusted for clinical covariates, were used to identify predictors of VA decline. Predictive performance was evaluated using time-dependent receiver operating characteristic (ROC) analysis. Kaplan-Meier survival and Cox regression analyses across ISI-based risk strata further evaluated time-to-visual-decline relationships. Baseline ISI was a significant predictor of both ≥ 5-letter (HR: 1.84, 95

Purpose:To investigate the possible influence of repeated anti-VEGF injections on vascular metrics measured by optical coherence tomography angiography (OCTA) in patients with age-related macular degeneration (AMD). Methods:This retrospective longitudinal study included AMD patients with a follow-up time of at least 18 months from 2019 to 2024. Swept-source OCTA was performed on all eyes. Based on whether an eye received injections or not during follow-up, all eyes were divided into two groups (non-injection group only included non-exudative AMD). Vessel density, Vessel skeleton density in the superficial, deep, and retina slab, as well as foveal avascular zone (FAZ) size, circularity and perimetry of Angio 6mm×6mm were calculated. Change in vascular metrics between baseline and last follow-up were compared between the two groups using t-test or Mann-Whitney U-test. Correlation between change in vascular metrics and visual acuity was investigated by Spearman's Rank Correlation test. Results:A total of 164 eyes from 107 patients were included. The average follow-up time was 34 months. No statistically significant difference in baseline vascular metrics was detected between the injection group (57 eyes) and non-injection (107 eyes) group. The injection group received 12.56 injections during follow-up. Among all the parameters, only change in FAZ size during follow-up showed a statistically significant difference between the two groups (0.03 vs. 0.02 mm2, P=0.043). No correlation was found between change in vascular metrics and change in visual acuity (P>0.05). Conclusion:In this retrospective longitudinal study of 164 eyes, repeated intravitreal anti-VEGF injections were associated with no relevant significant changes in OCTA vascular metrics over time.

To assess the association among retinal imaging biomarkers on expanded field swept-source optical coherence tomography angiography (EF SS-OCTA) and non-ocular microvascular complications of diabetes mellitus (DM). This retrospective, cross-sectional study included 146 eyes from 100 adults with diabetes mellitus (DM), across various stages of diabetic retinopathy. Patients were imaged with EF SS-OCTA (6 × 6 mm, Montage 15 × 15 mm). Mixed effect logistic models were used to identify SS-OCTA metrics associated with the occurrence of non-ocular microvascular complications, while controlling for age, DM duration, and types of treatment that patients received prior to their appointment. Patients’ eyes were treated as random effects, while metrics like ischemia index (Ratio ischemia index = pixels of the NPAs (nonperfusion areas) / pixels of the total image area) and neovascularization real area were rescaled for interpretability. NV (neovascular) VD (vessel density) and VSD (vessel skeletonized density) values are the VD and VSD only of the manually outlined areas of neovascularization. VD is the total area of perfused vasculature per unit area in a region of measurement, while VSD is the total length of perfused vasculature per unit area in a region of measurement. 54 patients had diabetic peripheral neuropathy (DPN), 25 had neither DPN nor diabetic kidney disease (DKD) and 17 had DKD. NV VSD and NV VD (OR = 2.45, p = 0.001) were significantly associated with both DPN and DKD combined (OR = 2.45, p = 0.003; OR = 2.45, p = 0.001, respectively) as well as in separate analyses of DPN (OR = 1.68, p = 0.033; OR = 1.73, p = 0.018, respectively) and DKD (OR = 2.19, p = 0.007; OR = 2.23, p = 0.002, respectively) alone. Ratio Ischemia index (OR: 1.75, p = 0.028) was significantly associated only with DPN. NV VSD and NV VD were significantly associated with both DPN and DKD while ratio ischemia index was only significantly associated with DPN, underscoring the potential utility of EF SS-OCTA metrics in predicting and monitoring non-ocular microvascular complications in clinical practice.

PURPOSE:To investigate associations among expanded field swept-source optical coherence tomography angiography biomarkers and the development of tractional retinal detachment (TRD) in patients with proliferative diabetic retinopathy (PDR). METHODS:Patients with PDR without TRD at baseline were imaged with swept-source optical coherence tomography angiography. Quantitative and qualitative OCTA metrics were independently evaluated by two trained graders. A logistic regression model was used to identify OCTA biomarkers associated with TRD development. RESULTS:Forty-nine PDR eyes from 38 participants were included. Seven of 49 eyes (14%) developed TRD over a median of 576 (range 35-805) days. Biomarkers associated with TRD were large retinal nonperfusion area (odds ratio [OR], 7.84; 95% confidence interval [CI], 2.61-16.3; P = 0.04), presence of neovascularization (NV) with total area > 4 disc diameters (OR, 2.30; 95% [CI], 1.09-4.51; P = 0.04), and presence of tabletop NV (OR, 2.64; 95% [CI], 1.42-4.86; P = 0.02), defined as NV displaced anteriorly by vitreous traction but tethered to the retina by vascular membranes. CONCLUSION:Presence of large retinal nonperfusion area, extensive NV, and NV with features of anterior displacement by vitreous traction were associated with increased risk of TRD occurrence. Swept-source optical coherence tomography angiography may be useful for predicting diabetic TRD development.

Purpose:The purpose of this study was to explore the possibility of using metadata from optical coherence tomography angiography (OCTA) for axial length (AL) estimation. Methods:This retrospective, cross-sectional, observational study included patients with both OCTA imaging and biometry measurements available in a single tertiary medical center from 2019 to 2024. Univariate and multivariate regression analyses were used to build the estimation model of AL using metadata from OCTA. Results:A total of 198 eyes from 130 patients were included. The average AL was 24.58 mm (interquartile range [IQR] = 22.35-26.81). Univariate regression analysis identified that y_chinrest, z_chinrest, z_lens, and z_motor were all closely related to AL (P < 0.001). The final estimation model derived from multivariate regression analysis was Axial_Length = 24.79611 - 0.25510 × y_chinrest - 0.23443 × z_chinrest - 1.41824 × z_lens + 0.71947 × z_motor. The multiple R-squared value was 0.5586 and adjusted R-squared value was 0.5495. Of the predicted values, 68.7% were within 1 mm of the true AL, and 92.9% were within 2 mm of the true AL. Regression diagnostic plots confirmed assumptions of linearity, homoscedasticity, normality, and no multicollinearity were met. Foveal avascular zone (FAZ) correction with estimated AL showed a reduction in mean absolute error by 31%, from 0.031 mm2 to 0.021 mm2 (P < 0.001). Conclusions:The present study demonstrates the possibility of reliable AL estimation using metadata from OCTA.

Purpose: To assess repeatability of macular inner choroid flow deficit percentage in intermediate age-related macular degeneration and controls using various postprocessing approaches. Methods: Cross-sectional, observational study. The authors included 1) 22 intermediate age-related macular degeneration and 24 control eyes, with 2) age >50 years, 3) visual acuity >20/32, and 4) no additional ocular and systemic confounders. Participants underwent four consecutive 6 × 6-mm optical coherence tomography angiography scans (2 acquired at 100-kHz and 2 at 200-kHz speed; PLEX Elite 9000) for intrasession analysis. Same protocol was repeated after 30 minutes for intersession analysis. Three slabs of different thicknesses were generated underneath Bruch membrane (4–14, 4–19, 4–24 µm). All slabs were processed with: 1) binarization-only using Phansalkar method (r = 4–15 pixels); 2) compensation + binarization; 3) averaging + binarization; 4) averaging + compensation + binarization. Inner choroid flow deficit percentage was measured within 3-mm and 5-mm circles, and measurements were repeated after excluding drusen areas. Repeatability was analyzed with generalized linear mixed-effects models, intraclass correlation coefficients, and Levene variance test. Results: Most postprocessing approaches demonstrated high repeatability (intraclass correlation coefficient >0.75) with no significant test–retest differences (P > 0.05). Compensation + binarization of 15-µm slabs at 200 kHz showed the highest repeatability (intraclass correlation coefficient: 0.96–0.98). Excluding drusen did not significantly affect inner choroid flow deficit percentage measurements (P > 0.05), showing increased intraclass correlation coefficients for 10-µm-thick and binarized-only slabs. Conclusion: Strong repeatability can be achieved with various postprocessing methods for assessing inner choroid flow deficit percentage, especially with compensation + binarization of 15-µm slabs acquired at 200 kHz. Drusen removal does not seem to affect repeatability in intermediate age-related macular degeneration when using a swept-source device, except for specific settings. These results contribute to refining choriocapillaris assessment, paving the way for future applications.

PURPOSE:To assess the severity and clinical significance of intraretinal microvascular abnormalities (IRMAs) using expanded field swept-source OCT angiography (SS-OCTA) in eyes with nonproliferative diabetic retinopathy (NPDR). DESIGN:Cross-sectional, observational study. PARTICIPANTS:One hundred thirty-nine eyes from 101 subjects with NPDR. METHODS:The montage of 12 × 12-mm angiography centered on the macula and optic nerve was evaluated by 2 masked graders for (1) the presence of IRMA in each 6 × 6-mm field, including center, superotemporal, inferotemporal, superonasal (SN), and inferonasal (IN) to the macula, and SN and IN to the optic nerve and (2) subtypes of IRMA (dilated trunk, net shape, loop, sea fan, and tufted IRMA). Nonperfusion areas (NPA) were quantified using FIJI. Nonproliferative diabetic retinopathy grading was initially collected from chart diagnoses and subsequently verified using ultra-widefield color fundus photos. Logistic and linear regression models were used to evaluate the relationships between IRMA features, diabetic retinopathy (DR) severity, and NPA. MAIN OUTCOME MEASURES:Intraretinal microvascular abnormality features associated with severe NPDR. RESULTS:Intraretinal microvascular abnormalities, observed with SS-OCTA, were present in 58.3% of all NPDR eyes and more prevalent in severe (96.6%) than mild (28.8%) to moderate (70.6%) NPDR. The number of affected fields and IRMA subtypes increased with DR severity (P < 0.01). The most common subtype of IRMA is the dilated trunk, comprising 58.3%, followed by the net shape subtype at 35.3%, loop at 11.5%, sea fan at 6.5%, and tufts at 5.8%. Significant predictors of severe NPDR included the presence of IRMA in the central field (odds ratio [OR]: 8.7; P = 0.01), more widely distributed IRMA (OR: 2.2; P < 0.01), a greater variety of IRMA subtypes (OR: 4.2, P < 0.01), and the presence of specific subtypes such as net shape (OR: 16.1; P = 0.02), sea fan (OR: 26.0; P < 0.01), and tufted IRMA (OR: 13.4; P = 0.03). Center-involving IRMA (β = 5.8; P = 0.046) and IRMA with loops (β = 7.0; P = 0.043) were found to be associated with increased NPA. CONCLUSIONS:Our study demonstrates that IRMA lesions identified on OCT angiography, particularly their distribution and morphology, are associated with DR severity and provide complementary information that may facilitate the integration of SS-OCTA into clinical evaluation of DR. FINANCIAL DISCLOSURE(S):Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Background: Best-corrected visual acuity (BCVA) is the current gold standard of retinal function measurement but is not affected in early and intermediate forms of age-related macular degeneration (AMD). Increasing evidence suggests that microperimetry is a sensitive measure of visual function. This study sought to analyze the associations between plasma and urine metabolites and microperimetry in AMD. Methods: We included data on 363 eyes (95 controls, 268 AMD). Microperimetry was performed in patients with or without AMD using the Macular Integrity Assessment (MAIA) microperimetry system, employing a 37-point full-threshold protocol. Plasma and urine samples were analyzed via ultra-high-performance liquid chromatography–mass spectrometry. Multilevel mixed-effects linear models were used to assess associations between the metabolites and retinal sensitivity. Statistical significance was determined by considering the number of independent tests that accounted for 80% of the variance (ENT80). Results: We identified two plasma and seven urine metabolites, which were significantly associated with mean retinal sensitivity in AMD, and the key results include metabolites in the lysine metabolism pathway. Conclusions: To our knowledge, we present the first assessment of the associations between plasma and urinary metabolites and retinal microperimetry sensitivity in AMD. This work can reveal more insight into the pathogenesis of AMD.

Purpose: To highlight the clinical utility of ultra-widefield swept-source optical coherence tomography angiography (SS-OCTA) in evaluating diabetic retinopathy (DR), particularly focusing on its ability to detect peripheral ischemia and neovascularization. Methods: Eyes of 5 participants with varying severity of DR were imaged with expanded-field 12 × 12-mm SS-OCTA scans and ultra-widefield SS-OCTA montages. Montages were created by stitching five 21 × 26-mm scans, offering up to a 200° field of view. Cases were assessed for areas of nonperfusion, intraretinal microvascular abnormalities, and neovascularization extending beyond the posterior pole. Results: Ultra-widefield SS-OCTA imaging demonstrated progressive mid-peripheral and peripheral nonperfusion, intraretinal microvascular abnormalities, and neovascularization in association with increasing DR severity. Peripheral nonperfusion and neovascular changes were detected beyond the scope of standard 12 × 12-mm scan areas. Conclusions: Ultra-widefield SS-OCTA is effective in noninvasively detecting peripheral retinal lesions such as ischemia and neovascularization. This technology offers potential to refine DR staging, improve risk stratification, and guide earlier clinical interventions.

Purpose: To describe a case of a drusenoid pigment epithelial detachment that resolved after retinal detachment (RD) repair using multimodal imaging. Methods: A single case was evaluated. Results: An 83-year-old woman with intermediate age-related macular degeneration had repair of a rhegmatogenous RD with subsequent resolution of macular drusen and improved visual acuity and metamorphopsia. Conclusions: RD repair may be associated with resolution of drusen, leading to improved functional outcomes.

PURPOSE:To longitudinally assess changes in macular thickness and microvascular metrics in retinal artery occlusion (RAO) patients, and to identify imaging biomarkers associated with visual prognosis. DESIGN:Retrospective cohort study. PARTICIPANTS:56 RAO patients (57 eyes) and 27 controls (30 eyes). METHODS:Comprehensive ophthalmic evaluations were performed, including macular OCT and 6 × 6 mm swept-source OCT angiography (SS-OCTA). Retinal thickness, macular ischemic area, ischemia-fovea distance, vessel skeletonized density (VSD), vessel density (VD), and foveal avascular zone (FAZ) area were quantified. Receiver operating characteristic (ROC) and linear regression analyses assessed imaging biomarkers correlated with visual outcomes. MAIN OUTCOME MEASURES:Longitudinal changes in retinal structure and microvasculature, and their associations with final visual acuity (VA). RESULTS:Among 57 RAO eyes (28 BRAO) with a median follow-up of 83.0 (35.5, 172.0) weeks, retinal thickness significantly decreased over time (P < .05), while macular ischemic area expanded from 64.97% to 73.58% (P = .002). In a subset of 24 RAO eyes with longitudinal SS-OCTA scans, eyes with a baseline ischemic area ≤ 1/3 of the scan area showed increased VSD and VD in both plexuses over time (P < .05). FAZ area was significantly larger in CRAO compared to BRAO (P = .0001), although no statistically significant change in FAZ area was observed over time (P = .341), a numerical increase was noted in CRAO cases. Better baseline VA, greater ischemic distance to fovea, smaller initial ischemic area, higher VSD and VD in SCP, and smaller FAZ area were associated with better final VA (all P < .05, AUC: 0.80-0.89). Multivariable linear regression identified baseline ischemic area and FAZ area as independent predictors of final VA (P = .003, 0.008). CONCLUSIONS:Multimodal quantification demonstrates the progressive ischemia in RAO and potential reperfusion in eyes with limited involvement. Ischemic area and FAZ area are key imaging biomarkers for visual prognosis.

Purpose: To assess repeatability of macular inner choroid flow deficit percentage in intermediate age-related macular degeneration and controls using various postprocessing approaches. Methods: Cross-sectional, observational study. The authors included 1) 22 intermediate age-related macular degeneration and 24 control eyes, with 2) age >50 years, 3) visual acuity >20/32, and 4) no additional ocular and systemic confounders. Participants underwent four consecutive 6 x 6-mm optical coherence tomography angiography scans (2 acquired at 100-kHz and 2 at 200-kHz speed; PLEX Elite 9000) for intrasession analysis. Same protocol was repeated after 30 minutes for intersession analysis. Three slabs of different thicknesses were generated underneath Bruch membrane (4-14, 4-19, 4-24 mu m). All slabs were processed with: 1) binarization-only using Phansalkar method (r = 4-15 pixels); 2) compensation + binarization; 3) averaging + binarization; 4) averaging + compensation + binarization. Inner choroid flow deficit percentage was measured within 3-mm and 5-mm circles, and measurements were repeated after excluding drusen areas. Repeatability was analyzed with generalized linear mixed-effects models, intraclass correlation coefficients, and Levene variance test. Results: Most postprocessing approaches demonstrated high repeatability (intraclass correlation coefficient >0.75) with no significant test-retest differences (P > 0.05). Compensation + binarization of 15-mu m slabs at 200 kHz showed the highest repeatability (intraclass correlation coefficient: 0.96-0.98). Excluding drusen did not significantly affect inner choroid flow deficit percentage measurements (P > 0.05), showing increased intraclass correlation coefficients for 10-mu m-thick and binarized-only slabs. Conclusion: Strong repeatability can be achieved with various postprocessing methods for assessing inner choroid flow deficit percentage, especially with compensation + binarization of 15-mu m slabs acquired at 200 kHz. Drusen removal does not seem to affect repeatability in intermediate age-related macular degeneration when using a swept-source device, except for specific settings. These results contribute to refining choriocapillaris assessment, paving the way for future applications.

Purpose To investigate structure-function associations between contrast sensitivity (CS) and widefield swept-source optical coherence tomography angiography (WF SS-OCTA) vascular metrics across stages of non-proliferative (NPDR) and proliferative diabetic retinopathy (PDR), without diabetic macular oedema. Methods Prospective cross-sectional study in 140 eyes of 99 patients: 33 mild NPDR, 24 moderate/severe NPDR, 15 PDR, 33 diabetic without DR (DMnoDR) and 46 control eyes. Mixed-effects multivariable regression models to evaluate associations between quantitative contrast sensitivity function (Adaptive Sensory Technology) and vessel density (VD) and vessel skeletonised density (VSD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) on same-day imaging with WF SS-OCTA (Plex Elite 9000, Carl Zeiss Meditec). Results Standardised beta coefficients for area under the logarithm of contrast sensitivity function curve (AULCSF) versus visual acuity (VA) at 3x3mm scans: SCP VSD (beta=0.32, p<0.001 vs -0.18, p=0.044), DCP VSD (beta=0.30, p<0.001 vs -0.21, p=0.02), SCP VD (beta=0.25, p=0.004 vs -0.13, p=0.129), DCP VD (beta=0.26, p=0.003 vs -0.19, p=0.034). AULCSF was significantly reduced in mild NPDR (beta=-0.28, p<0.001) and DMnoDR (beta=-0.19, p=0.005) versus controls, while VA was not significantly different. AULCSF performed better than VA in differentiating between controls and DMnoDR (0.69 vs 0.50), controls and mild NPDR (0.76 vs 0.61) and controls and moderate/severe NPDR (0.89 vs 0.73). Conclusions DR-induced microvascular changes on OCTA are associated with larger changes on CS than in VA. CS is affected earlier than VA in the course of DR and performed better in discriminating between controls, DMnoDR and across DR stages.