1.
Capillary density and caliber as assessed by optical coherence tomography angiography may be significant predictors of diabetic retinopathy severity.
Kushner-Lenhoff, S, Kogachi, K, Mert, M, Chu, Z, Shahidzadeh, A, Palejwala, NV, Wolfe, J, Itty, S, Drenser, KA, Capone, A, et al
PloS one. 2022;(1):e0262996
Abstract
PURPOSE To validate retinal capillary density and caliber associations with diabetic retinopathy (DR) severity in different clinical settings. METHODS This cross-sectional study assessed retinal capillary density and caliber in the superficial retinal layer of 3-mm OCTA scans centered on the fovea. Images were collected from non-diabetic controls and subjects with mild or referable DR (defined DR worse than mild DR) between February 2016 and December 2019 at secondary and tertiary eye care centers. Vessel Skeleton Density (VSD), a measure of capillary density, and Vessel Diameter Index (VDI), a measure of vascular caliber, were calculated from these images. Discriminatory performance of VSD and VDI was evaluated using multivariable logistic regression models predicting DR severity with adjustments for sex, hypertension, and hyperlipidemia. Area under the curve (AUC) was estimated. Model performance was evaluated in two different cohorts. RESULTS This study included 594 eyes from 385 subjects. Cohort 1 was a training cohort of 509 eyes including 159 control, 155 mild non-proliferative DR (NPDR) and 195 referable DR eyes. Cohort 2 was a validation cohort consisting of 85 eyes including 16 mild NPDR and 69 referable DR eyes. In Cohort 1, addition of VSD and VDI to a model using only demographic data significantly improved the model's AUC for discrimination of eyes with any DR severity from controls (0.91 [95% CI, 0.88-0.93] versus 0.80 [95% CI, 0.76-0.83], p < 0.001) and eyes with referable DR from mild NPDR (0.90 [95% CI, 0.86-0.93] versus 0.69 [95% CI, 0.64-0.75], p < 0.001). The transportability of this regression model was excellent when implemented in Cohort 2 for the referable DR versus mild NPDR comparison. The odds ratio of having any DR compared to control subjects, and referable DR compared to mild DR decreased by 15% (95% CI: 12-18%), and 13% (95% CI: 10-15%), respectively, for every 0.001 unit increase in VSD after adjusting for comorbidities. CONCLUSION OCTA-derived capillary density has real world clinical value for rapidly assessing DR severity.
2.
Effects of Rosuvastatin and Aspirin on Retinal Vascular Structures in Hypercholesterolemic Patients with Low-to-Moderate Risk of Coronary Artery Disease.
Li, L, Wang, S, Huang, H, Cai, Y, Xi, Y, Bai, Y, Ma, C
American journal of cardiovascular drugs : drugs, devices, and other interventions. 2019;(4):415-420
Abstract
INTRODUCTION Atherosclerosis erodes large elastic arteries and damages peripheral small vessels. Evaluating retinal vessel caliber enables exploration of the effect of improving microcirculation with statins. OBJECTIVE We investigated whether rosuvastatin therapy improves retinal vasculature in hypercholesterolemic patients with a low-to-moderate risk of coronary artery disease (CAD). METHODS This was a prospective, open-label, randomized study in which 127 patients were enrolled and randomized (ratio 1:1) into rosuvastatin and control groups. RESULTS Rosuvastatin increased retinal arteriolar calibers by 3.560 µm at 12 months, decreased retinal venular calibers by 3.110 µm at 6 months and by 5.860 µm at 12 months, and increased the artery-vein ratio (AVR) by 2.68% at 6 months and by 5.90% at 12 months. Meanwhile, in the control group, retinal arteriolar calibers decreased by 1.110 µm at 12 months, retinal venular calibers increased by 1.020 µm at 6 months and by 1.04 µm at 12 months, and AVR decreased by 1.12% at 6 months and by 1.73% at 12 months. All the above parameters were statistically significant between groups, but there was no significant change in retinal arteriolar calibers at 6 months. The increased AVR correlated significantly with decreased C-reactive protein (CRP) at 6 months and decreased low-density lipoprotein and CRP at 12 months. DISCUSSION For patients with a low-to-moderate risk of CAD, we found a significant effect of rosuvastatin on retinal microvasculature, including AVR increase, venular constriction, and arteriolar dilation after 6-12 months of treatment. CLINICAL TRIAL REGISTRATION Chinese Clinical Trial Registry identifier number ChiCTR-IOR-15006664.
3.
Topical Treatment With Brimonidine and Somatostatin Causes Retinal Vascular Dilation in Patients With Early Diabetic Retinopathy From the EUROCONDOR.
Grauslund, J, Frydkjaer-Olsen, U, Peto, T, Fernández-Carneado, J, Ponsati, B, Hernández, C, Cunha-Vaz, J, Simó, R, ,
Investigative ophthalmology & visual science. 2019;(6):2257-2262
Abstract
PURPOSE Structural retinal microvascular changes have been identified as risk markers of diabetic retinopathy (DR). In order to estimate the retinal response of neuroprotective eye drops, we aimed to evaluate the effect of topical retinal neuroprotection on retinal microvascular changes in early DR. METHODS Patients with type 2 diabetes with no or early DR were randomized 1:1:1 to topical treatment with placebo, brimonidine, or somatostatin in a 96-week prospective, phase II to III, European multicenter trial. Retinal vascular calibers were measured semiautomatically in digital fundus images by certified graders at baseline and follow-up and summarized as central retinal arteriolar and venular equivalent (CRAE and CRVE). RESULTS Of 449 patients originally included, 297 completed the study with gradable retinal images. Median age and duration of diabetes was 64.5 and 9.9 years, and 65.7% were male. At baseline, Early Treatment Diabetic Retinopathy Study levels were 10 (no DR, 42.8%), 20 (minimal DR, 28.3%), and 35 (mild DR, 29.0%), and CRAE and CRVE did not differ between groups. As opposed to patients with no or minimal DR at baseline, patients with mild DR in the active groups developed a larger retinal arteriolar (brimonidine: +6.2 μm, P = 0.006; somatostatin: +7.2 μm, P = 0.006) and venular (brimonidine: +13.9 μm, P = 0.01; somatostatin: +14.3 μm, P = 0.0001) caliber in contrast to those in the placebo group. CONCLUSIONS Topical treatment with brimonidine and somatostatin causes retinal arteriolar and venular dilation in patients with type 2 diabetes and preexisting early DR. Upcoming studies should elaborate on the potential of these findings in arresting early DR.