Abstract
Purpose :
While funduscopic abnormalities may serve as an early indicator of hypertension, early stages of hypertensive retinopathy are difficult to clinically distinguish. Prior studies suggest that peri-foveal tortuosity may be a marker of early retinal changes in patients with hypertension. Optical coherence tomography angiography (OCT-A) is non-invasive and provides high-resolution imaging of retinal and choroidal vasculature that may serve as a useful tool in detecting early-stage hypertensive retinopathy not captured by the current Scheie classification criteria.
Methods :
Single center OCT-A images from 20 hypertensive and 21 control patients were obtained retrospectively. Two ophthalmologists graded randomized eyes according to the Scheie classification. Cohen’s weighted kappa was calculated to assess inter-observer agreement for tortuosity. Two raters used ImageJ software to measure arc and chord length for at most three peri-foveal arterioles and venules to the first branch point or within a 2500µm radius of the center of the fovea. The ratio of arc to cord length was calculated to determine vessel tortuosity. The Fleiss Multirater Kappa (FMK) was calculated between raters and the Mann-Whitney U (MWU) test was performed to assess the difference in tortuosity between the control and hypertensive groups for arterioles and venules separately.
Results :
Among 41 patients who received OCT-A imaging (Mean age=67.80 [SD=11.29] years, 63.41% female), no statistical differences were found in age or sex. The MWU test demonstrated no significant difference in peri-foveal tortuosity of venules between the hypertensive and control groups (Mean=1.130 vs. 1.129, p=0.876), but did demonstrate a significant difference for arterioles (Mean=1.139 vs. 1.110, p=0.035). Tortuosity measurements demonstrated a significant inter-observer agreement (kappa = 0.647) while Scheie ratings had a poor inter-observer agreement (kappa = -.0603). The MWU test demonstrated a significant increase in Scheie classification between the two groups (Mean= 0.986 [SD= 0.503] vs. 0.500 [SD= 0.426], p= 0.005).
Conclusions :
Given the importance of screening and early detection of hypertensive retinopathy, as well as poor inter-rater reliability of the Scheie criteria, these results suggest that peri-foveal tortuosity of arterioles may be helpful for the assessment of systemic hypertensive retinopathy.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.