Impact of systemic hypertension on retinal and choroidal microvasculature using OCT Angiography

Abstract

AbstractIn this cross‐sectional study, we measured the retinal and choroidal microvasculature using the optical coherence tomographic angiography (OCTA) in 77 adults (n = 153 eyes) with systemic hypertension (mean [SD] age, 58 [9] years; 49% women; 23% poorly controlled BP) who are without ocular diseases and determined correlations with systemic vascular risk factors. Data on 24‐hr ambulatory blood pressure (BP) monitoring, serum creatinine, and urine microalbumin/creatinine ratio (MCR) were collected. Estimated glomerular filtration rate (eGFR) was calculated based on CKD‐EPI Creatinine Equation. OCTA imaging (6 × 6 mm macular scans; AngioVue) with quantitative retinal capillary densities (superficial and deep vascular plexuses; SVP and DVP) and choriocapillaris flow voids (area, size and number) were obtained. Linear regression was used to investigate the association of risk factors with microvascular analysis. Higher systolic BP was correlated with sparser retinal capillary density (β = −0.23, −0.44 to −0.02) and smaller areas of flow voids (β = −0.13, −0.24 to −0.02). Also, higher diastolic BP was correlated with flow voids that were smaller in individual size (β = −0.18, −0.34 to −0.02) but more numerous (β = 13.89, 0.61–27.17). Lower eGFR was correlated with sparser retinal capillary density (β = 6.42, 1.25–11.60) whereas renal parameters were not associated with flow voids. In patients with hypertension, higher BP appeared to cause retinal capillary dropout but increase blood flow in the choriocapillaris, which needs to be further investigated. Changes in the retinal microvasculature may reflect kidney function, which highlights the potential of using the OCTA to study early systemic microvascular changes.