Characterization of hypertensive vascular features in the retina of women with preeclampsia

Abstract

Purpose : Preeclampsia is a hypertensive disorder of pregnancy and remains a leading cause of maternal morbidity and mortality worldwide. The maternal cardiovascular dysfunction present in preeclampsia can be manifested in the retina. Our purpose is to characterize hypertensive vascular features in the retina of women with preeclampsia using ultra-widefield retinal imaging and advanced image processing techniques.

Methods : This is a prospective case-control design in women with preeclampsia between 24 and 33 weeks of gestation and admitted for management and gestationally matched healthy pregnant women as controls. Fundus imaging was performed using a non-mydriatic ultra-widefield camera. Assessment of the retinal vascular was performed with two approaches: 1) masked readers graded the presence or absence of hypertension-related vascular lesions (i.e., arterio-venous nicking, focal arteriolar narrowing, and other retinopathy); 2) custom algorithms were developed to quantify the tortuosity of vasculature including the mean and maximum vessel tortuosity index (VTI), and the mean and maximum distance measure (DM). DM was calculated by the ratio of vessel length to its chord length, and VTI was based on the local and global parameters extracted from the centerline. Analysis was performed using a non-parametric Mann-Whitney U test to compare cases and controls. Linear discriminant analysis was performed based on our quantitative measures.

Results : Preliminary data on five cases (25.2 ± 8.0 years) and five controls (28.2 ± 7.1 years) showed a high correlation in findings between right and left eyes (R>0.67). Hypertension-related vascular lesions in the retina images were seen in all cases and three controls. The two controls with normal retinal vessels showed the lowest VTI and DM among all subjects. In this small sample size, there was no difference in VTI and DM between preeclampsia cases and controls. Linear discriminant function based on the mean VTI, maximum VTI, mean DM, and maximum DM had 10% misclassification with entropy R-square of 0.48.

Conclusions : This pilot study established methods to characterize preeclampsia-associated vascular features in the retina that combined clinical phenotyping as a binary trait and tortuosity of vasculature. As the sample size is increased, we will determine the association between retina imaging features of hypertensive retinopathy and severe preeclampsia.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.