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Purpose: To determine the contribution of retinal vessel density (VD), central retinal vessel diameter and retinal oxygen (O2) saturation independently of other known risk factors in the development of non‐proliferative diabetic retinopathy (NPDR). Methods: Macular optical coherence tomography angiography (OCTA), central retinal artery/vein equivalent diameter (CRAE/CRVE) measurements and retinal oximetry were performed in a cross‐sectional study of 166 eyes from 166 individuals with type 1 diabetes (T1D) aged 14–30 years. Multiple logistic regression analysis was used to investigate whether O2 saturation, retinal vessel diameters and vessel density in the deep capillary plexus (VD‐DCP) were associated with NPDR, when adjusting for known risk factors. The individuals were allocated to one group without and one group with NPDR. Results: Multiple logistic regression analysis showed that age (OR = 1.25, 95% CI: 1.04–1.49) and AV‐difference in O2 saturation (OR = 0.85, 95% CI 0.77–0.93) were significantly associated with NPDR. Conclusion: Our findings suggest that age and lower AV‐O2 saturation difference contribute to explaining the grade of NPDR independently of other well‐known risk factors. Reduced delivery of O2 to the retinal tissue is associated with the development of NPDR in young patients with T1D and should be given appropriate weight in the risk stratification at early stages of the disease. [ABSTRACT FROM AUTHOR]

Purpose: To clarify how early in the development of diabetic retinopathy (DR) can oxygen (O2) saturation changes be detected. Methods: Retinal oximetry was performed in a cross‐sectional study, involving 14‐ to 30‐year‐old individuals: 185 with type 1 diabetes (T1D) and 94 controls. The subjects were divided into four groups according to the grade of DR. One‐way ANOVA and post hoc tests were used to test for differences in the mean O2 saturations between the groups. Results: Fifty‐eight (31 %) of the T1D patients had nonproliferative DR. There was no significant difference in O2 saturations between controls and T1D patients with no DR. Arteriolar and venular O2 saturations in T1D patients were significantly higher in moderate/severe DR than in no DR (p = 0.009 and p > 0.001), while venular O2 saturation was significantly higher in mild DR than in no DR (p = 0.013). Conclusion: Increase in venular O2 saturation could not be detected before mild retinopathy had developed, and the retinal O2 saturation increase was measurable on the venular side first. Our results suggest that the increase in O2 saturation is likely a consequence of DR. [ABSTRACT FROM AUTHOR]

Background/Objective. Optical coherence tomography angiography (OCTA) is increasingly used to supplement ophthalmoscopy in the diagnosis and follow-up of diabetic retinopathy. Our objective was to confirm if OCTA parameters can predict the development of nonproliferative diabetic retinopathy (NPDR) and to clarify if any single OCTA parameter is associated with NPDR independently of well-known risk factors in young type 1 diabetes (T1D) patients. Methods. OCTA of both eyes was performed in a cross-sectional study of 14 to 30-year-old individuals with at least 10-year duration of T1D and controls recruited from the Norwegian Atherosclerosis and Childhood Diabetes (ACD) study. Vessel density (VD) and foveal avascular zone (FAZ) area in the superficial and deep capillary plexus (SCP and DCP), total retinal volume (TRV), and central macular thickness (CMT) were calculated using automated software. Univariate and multivariate ordered logistic regression (OLR) models were used accordingly. Results. We included 168 control eyes and 315 T1D eyes. Lower VD in DCP (OR 0.65, 95% CI 0.51–0.83), longer diabetes duration (OR 1.51, 95% CI 1.22–1.87), and higher waist circumference (OR 1.08, 95% CI 1.02–1.14) were significantly associated with progression of NPDR. VD in SCP and DCP were significantly lower in T1D patients without diabetic retinopathy than in controls. Conclusions. Sparser VD in DCP is significantly associated with severity of NPDR, supporting that OCTA might detect the earliest signs of NPDR before it is visible by ophthalmoscopy. [ABSTRACT FROM AUTHOR]