Retinal Arteriolar Morphometry Based on Full Width at Half Maximum Analysis of Spectral-Domain Optical Coherence Tomography Images

Abstract

ObjectivesIn this study, we develop a microdensitometry method using full width at half maximum (FWHM) analysis of the retinal vascular structure in a spectral-domain optical coherence tomography (SD-OCT) image and present the application of this method in the morphometry of arteriolar changes during hypertension.MethodsTwo raters using manual and FWHM methods measured retinal vessel outer and lumen diameters in SD-OCT images. Inter-rater reproducibility was measured using coefficients of variation (CV), intraclass correlation coefficient and a Bland-Altman plot. OCT images from forty-three eyes of 43 hypertensive patients and 40 eyes of 40 controls were analyzed using an FWHM approach; wall thickness, wall cross-sectional area (WCSA) and wall to lumen ratio (WLR) were subsequently calculated.ResultsMean difference in inter-rater agreement ranged from -2.713 to 2.658 μm when using a manual method, and ranged from -0.008 to 0.131 μm when using a FWHM approach. The inter-rater CVs were significantly less for the FWHM approach versus the manual method (P < 0.05). Compared with controls, the wall thickness, WCSA and WLR of retinal arterioles were increased in the hypertensive patients, particular in diabetic hypertensive patients.ConclusionsThe microdensitometry method using a FWHM algorithm markedly improved inter-rater reproducibility of arteriolar morphometric analysis, and SD-OCT may represent a promising noninvasive method for in vivo arteriolar morphometry.

Early Signs of End‐Organ Damage in Retinal Arterioles in Patients with Type 2 Diabetes Compared to Hypertensive Patients

“…However, in the subgroup of patients with diabetes duration >60 months ID was similar and WT as well as CA greater compared to healthy individuals, which is consistent with the results obtained in subcutaneous arteriolar vessels [34]. Our findings of hypertrophic remodeling in the subgroup of patients with greater than 60 months diabetes duration are also in accordance with increased retinal WT found in the hypertensive diabetic population in Tong's et al [35] clinical investigation.…”

“…Our findings of hypertrophic remodeling in the subgroup of patients with greater than 60 months diabetes duration are also in accordance with increased retinal WT found in the hypertensive diabetic population in Tong's et al . clinical investigation.…”

“…Systolic office BP and CA as well as systolic office BP and WT also correlated in the diabetic group, demonstrating the modifying role of pressure on vascular remodeling. Hypertrophic remodeling has been previously described in diabetic patients based on ex vivo studies of biopsied subcutaneous arteriolar vessels [26,34], in retinal arterioles of patients with diabetic retinopathy [2], and in a small number of hypertensive diabetic patients [35]. Schofield reported in subcutaneous gluteal small arteries of patients with T2DM significantly greater media-to-lumen ratio and a significantly greater cross-sectional wall area compared to a healthy population [34].…”

“…Eutrophic remodeling has also been demonstrated in retinal arterioles of hypertensive patients using SLDF or adaptative optics retinal camera . Detailed analysis of an investigation with hypertensive patients revealed increased WT and WLR of retinal arterioles in a small number of hypertensive diabetic patients compared to healthy individuals, thereby suggesting retinal arteriolar hypertrophic remodeling . Accordingly, in patients with diabetic retinopathy thickening of retinal small arteriolar walls has been described using confocal AOSLO .…”

Comparative Study of Optical Coherence Tomography Angiography and Phase-Resolved Doppler Optical Coherence Tomography for Measurement of Retinal Blood Vessels Caliber

“… 9 – 11 OCT offers high spatial resolution, noninvasive imaging, and high-image acquisition rates, which allows for large field of view and cellular resolution imaging of the morphology of biological tissues. In the past, a number of studies have been conducted to measure the blood vessel caliber from cross-sectional OCT B-scans 12 – 18 or the shadow profiles of blood vessels. 19 Specifically, Ouyang et al 17 used OCT cross-sectional images for measuring RBVCs in a clinical study, and showed high correlation with data acquired with an infrared reflectance (IR) imaging system.…”