Deep Capillary Geometric Perfusion Deficits on OCT Angiography Detect Clinically Referable Eyes with Diabetic Retinopathy.

To evaluate the sensitivity (SN) and specificity (SP) of OCT angiography (OCTA) parameters for detecting clinically referable eyes with diabetic retinopathy (DR) in a cohort of patients with diabetes mellitus (DM). Retrospective, cross-sectional study. Patients with DM with various levels of DR. We measured vessel density, vessel length density (VLD), and geometric perfusion deficits (GPDs) in the full retina, superficial capillary plexus (SCP), and deep capillary plexus (DCP) on 3 × 3-mm OCTA images. Geometric perfusion deficit was recently described as retinal tissue located further than 30 μm from blood vessels, excluding the foveal avascular zone (FAZ). We modified the GPD metric by including the FAZ as an additional variable. Clinically referable eyes were defined as moderate nonproliferative DR (NPDR) or worse retinopathy, or diabetic macular edema (DME). One eye from each patient was selected for the analysis based on image quality. We used a binary logistic regression model to adjust for covariates. Sensitivity, SP, and area under the curve (AUC). Seventy-one of 150 included eyes from 150 patients (52 with DM without DR, 27 with mild NPDR, 16 with moderate NPDR, 10 with severe NPDR, 30 with proliferative DR, and 15 with DME) had clinically referable DR. Geometric perfusion deficit metric that included the FAZ performed better than GPD in detecting referable DR in the SCP (P = 0.025) but not the DCP or full retina (P > 0.05 for both). Deep capillary plexus GPD had the largest AUC for detecting clinically referable eyes (AUC = 0.965, SN = 97.2%, SP = 84.8%), which was significantly larger than the AUC for vessel density of any layer (P < 0.05 for all) but not DCP VLD (P = 0.166). The cutoff value of 2.5% for DCP GPD resulted in a highly sensitive test for detecting clinically referable eyes without adjusting for covariates (AUC = 0.955, SN = 97.2%, SP = 79.7%). Vascular parameters in OCTA, especially in the DCP, have the potential to identify eyes that warrant further evaluation. Geometric perfusion deficits may better distinguish these clinically referable eyes with DR than standard vessel density parameters.

Nesper PL ，Ong JX ，Fawzi AA 《-》

Macular Perfusion Deficits on OCT Angiography Correlate with Nonperfusion on Ultrawide-field Fluorescein Angiography in Diabetic Retinopathy.

To evaluate the correlation between nonperfusion parameters on OCT angiography (OCTA) and ultrawide-field fluorescein angiography (UWF-FA) in subjects with diabetes mellitus (DM). Prospective, cross-sectional study. Subjects with DM and a wide range of diabetic retinopathy (DR) severity seen at a tertiary referral center. We used averaged 3 × 3 mm OCTA scans to measure geometric perfusion deficit (GPD), vessel density, and vessel length density in the full retina, superficial capillary plexuses (SCPs), and deep capillary plexuses (DCPs). Nonperfusion was manually delineated on UWF-FA to quantify central, peripheral, and total retinal nonperfusion (mm2 and % area). Correlation between OCTA parameters and UWF-FA nonperfusion, and accuracy of these OCTA and UWF-FA parameters in detecting clinically referable eyes, using receiver operating characteristic (ROC) curve analysis, sensitivity, specificity, and area under the ROC curve (AUC). The study included 67 eyes (12 eyes with no signs of DR, 8 mild, 22 moderate, 14 severe nonproliferative DR, and 11 treatment-naive proliferative DR). There was a fair-to-moderate correlation between either central or total retinal nonperfusion on UWF-FA (mm2) and GPD in the SCP (r = 0.482 and r = 0.464, respectively) and DCP (r = 0.470 and r = 0.456, respectively). Receiver operating characteristic analysis showed the DCP GPD significantly superior to other OCTA parameters at the DCP with the largest overall AUC on OCTA for distinguishing referable DR (0.905). Furthermore, the GPD parameter had the largest AUC in each respective capillary layer compared with other parameters. Overall, the total UWF-FA nonperfusion area showed a comparable AUC (0.907) and performed significantly better than peripheral nonperfusion (P = 0.041). Comparing the AUC values between GPD and UWF-FA nonperfusion parameters showed no significant difference in discerning referable DR. Nonperfusion as quantified on OCTA (3 × 3 mm) correlated with UWF-FA parameters and both were comparable in detecting referable DR. These macular OCTA metrics, particularly DCP GPD, have the potential for gauging the overall ischemic status of the retina, with an important clinical role in identifying eyes with clinically referable DR. Proprietary or commercial disclosure may be found after the references.

Decker NL ，Duffy BV ，Boughanem GO ，Fukuyama H ，Castellanos Canales D ，Nesper PL ，Gill MK ，Fawzi AA ... -  《-》

Deep Capillary Nonperfusion on OCT Angiography Predicts Complications in Eyes with Referable Nonproliferative Diabetic Retinopathy.

To evaluate the ability of capillary nonperfusion parameters on OCT angiography (OCTA) to predict the development of clinically significant outcomes in eyes with referable nonproliferative diabetic retinopathy (NPDR). Prospective longitudinal observational study. In total, 59 patients (74 eyes) with treatment-naive moderate and severe (referable) NPDR. Patients were imaged with OCTA at baseline and then followed-up for 1 year. We evaluated 2 OCTA capillary nonperfusion metrics, vessel density (VD) and geometric perfusion deficits (GPDs), in the superficial capillary plexus, middle capillary plexus (MCP), and deep capillary plexus (DCP). We compared the predictive accuracy of baseline OCTA metrics for clinically significant diabetic retinopathy (DR) outcomes at 1 year. Significant clinical outcomes at 1 year, defined as 1 or more of the following-vitreous hemorrhage, center-involving diabetic macular edema, and initiation of treatment with pan-retinal photocoagulation or anti-VEGF injections. Overall, 49 patients (61 eyes) returned for the 1-year follow-up. Geometric perfusion deficits and VD in the MCP and DCP correlated with clinically significant outcomes at 1 year (P < 0.001). Eyes with these outcomes had lower VD and higher GPD, indicating worse nonperfusion of the deeper retinal layers than those that remained free from complication. These differences remained significant (P = 0.046 to < 0.001) when OCTA parameters were incorporated into models that also considered sex, baseline corrected visual acuity, and baseline DR severity. Adjusted receiver operating characteristic curve for DCP GPD achieved an area under the curve (AUC) of 0.929, with sensitivity of 89% and specificity of 98%. In a separate analysis focusing on high-risk proliferative diabetic retinopathy outcomes, MCP and DCP GPD and VD remained significantly predictive with comparable AUC and sensitivities to the pooled analysis. Evidence of deep capillary nonperfusion at baseline in eyes with clinically referable NPDR can predict short-term DR complications with high accuracy, suggesting that deep retinal ischemia has an important pathophysiologic role in DR progression. Our results suggest that OCTA may provide additional prognostic benefit to clinical DR staging in eyes with high risk.

Ong JX ，Konopek N ，Fukuyama H ，Fawzi AA ... -  《-》

Macular Capillary Perfusion in Chinese Patients With Diabetic Retinopathy Obtained With Optical Coherence Tomography Angiography.

To compare the macular perfusion in the retina and choroidal layer between control subjects and Chinese patients with diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA) and to evaluate the association of OCTA characteristics with the stage of DR. A total of 200 eyes (normal controls = 40; mild non-proliferative diabetic retinopathy [NPDR] = 40; moderate NPDR = 40; severe NPDR = 40; and PDR [proliferative diabetic retinopathy] = 40) underwent OCTA imaging. OCTA parameters were vessel densities in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris, as well as foveal avascular zone (FAZ) area (mm2) in the SCP. The reduction of macular perfusion in the SCP, DCP, and choriocapillaris was correlated with increasing severity of DR. Vessel density in the SCP, DCP, and choriocapillaris was 55.31% ± 2.56%, 62.40% ± 2.46%, and 66.87% ± 1.30%, respectively, in control subjects; 50.58% ± 3.14%, 56.31% ± 4.24%, and 66.20% ± 1.69%, respectively, in mild NPDR; 46.46% ± 3.09%, 49.40% ± 5.68%, and 64.39% ± 1.94%, respectively, in moderate NPDR; 45.61% ± 3.81%, 49.33% ± 6.14%, and 63.75% ± 2.21%, respectively, in severe NPDR; and 43.78% ± 3.71%, 44.78% ± 6.36%, and 61.32% ± 6.29%, respectively, in PDR. Vessel density in DR groups decreased compared with normal controls (P < .001). FAZ area in the SCP was 0.34 ± 0.09 mm2 in control subjects compared with 0.48 ± 0.17 mm2 (mild NPDR), 0.52 ± 0.13 mm2 (moderate NPDR), 0.62 ± 0.24 mm2 (severe NPDR), and 0.75 ± 0.30 mm2 (PDR). FAZ in the SCP of patients with DR was greater than that in control subjects (P < .001). Vessel density in the DCP shows better ability to identify the severity of DR (area under the curve, sensitivity, and specificity of 0.967, 92.5%, and 93.1%, respectively) than vessel density in the SCP and choriocapillaris. OCTA might be clinically useful to evaluate different stages of DR in a noninvasive manner. Vessel density in DCP could be an objective and reliable indicator for monitoring progression of DR. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:e88-e95.].

Yang D ，Cao D ，Huang Z ，Xie J ，Meng Q ，Dong X ，Hu Y ，Zeng Y ，Zhang L ... -  《-》

Macular vessels density in diabetic retinopathy: quantitative assessment using optical coherence tomography angiography.

AttaAllah HR ，Mohamed AAM ，Ali MA 《-》