Impact of Hypertension on Retinal Microvascular Changes on Optical Coherence Tomographic Angiography

Abstract

Purpose : Optical coherence tomographic angiography (OCT-A)-derived capillary density index (CDI) has been correlated with severity of glaucoma and diabetic retinopathy, but no studies have evaluated impact of hypertension on OCT-A measures. The purpose of this study was to evaluate the associations between OCT-A derived CDI on various systemic vascular risk factors, including blood pressure and renal parameters.

Methods : This is a cross-sectional clinical study of 77 Asian adults with hypertension without diabetes and ocular diseases (mean [SD] age, 58 [9] years; 51% women; 23% resistant hypertension). All patients underwent OCT-A (AngioVue; Optovue, Inc., USA), with an in-built quantitative measurement of CDI at superficial vascular plexus (SVP) and deep vascular plexus (DVP). Data on 24-hour ambulatory blood pressure, serum creatinine, and urine microalbumin/creatinine ratio (MCR) were collected. We assessed the associations between systemic factors with CDI using linear regression models with generalized estimating equations.

Results : Higher systolic (β = -0.21, 95% confidence interval (CI), -0.40 to -0.02; P=0.034) and diastolic (β = -0.32, 95% CI, -0.57 to -0.07; P=0.013) blood pressures were associated independently with reduced CDI at SVP, adjusted for age. Higher urine MCR was associated independently with reduced CDI at SVP (β = -0.0006; 95% CI, -0.0008 to -0.0004) and DVP (β = -0.004; 95% CI, -0.005 to -0.004), adjusted for age (both P<0.001). Lower estimated GFR (CKD-EPI Creatinine Equation) was associated with reduced CDI at SVP (β = 0.07; 95% CI, 0.01 to 0.13) and DVP (β = 0.09; 95% CI, 0.01 to 0.13), in univariate model (both P=0.005).

Conclusions : High blood pressures and abnormal renal parameters were associated with reduced CDI. These findings highlight the potential role of OCT-A to study early microvascular changes due to systemic hypertension.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.