Purpose
To assess the value of increased perifoveal retinal vascular tortuosity in optical coherence tomography angiography (OCTA) images as a biomarker of early hypertensive retinopathy and compare its clinical sensitivity and accuracy with traditional morphological changes used for Scheie classification.
Methods
OCTA images of 81 eyes (40 eyes from 20 hypertensive subjects and 41 eyes from 21 control subjects) were obtained retrospectively. Hypertensive retinopathy changes in randomized eyes were graded according to the Scheie classification, and perifoveal vessels were traced in a masked fashion. Tortuosity values of the perifoveal vessels were then calculated along with interobserver agreement in determining the morphometric values.
Results
There were no differences in perifoveal venular tortuosity between the hypertensive and control groups (Mean = 1.13 ± 0.04 vs. 1.13 ± 0.03), but significant differences existed for arterioles (Mean = 1.14 ± 0.05 vs. 1.11 ± 0.04). Tortuosity measurements demonstrated a significant interobserver agreement (p < 0.001), while Scheie ratings had a poor interobserver agreement (p = 0.735). There was a significant difference in Scheie classification between the hypertensive and control groups (Mean = 1.06 ± 0.54 vs. 0.50 ± 0.43, p = 0.005).
Conclusions
OCTA-based perifoveal retinal arteriolar tortuosity may be a potential reliable biomarker with certain advantages for detecting early hypertensive retinopathy than morphological changes used for the Scheie classification. This may have broad applications and establish important parameters in utilizing OCTA for screening protocols, considering the importance of early detection of systemic hypertension.
