Retinal and Choroidal Capillary Perfusion Are Reduced in Hypertensive Crisis Irrespective of Retinopathy

Abstract

Purpose: Hypertensive crisis causes end-organ damage through small-vessel damage as described histologically. Noninvasive optical coherence tomography angiography (OCTA) makes it possible to image retinal and choroidal capillaries on a microscopic level in vivo. We quantified eye vessel perfusion changes in hypertensive crisis using OCTA.

Methods: Patients with hypertensive crisis (systolic blood pressure ≥180 mm Hg and/or diastolic blood pressure ≥110 mm Hg) and age-matched healthy controls were included in the study. OCTA en face 3 × 3-mm images of the superficial and deep retinal layers and the choriocapillaris were acquired. Outcome parameters included vessel density (VD) and vessel skeleton density (VSD) of the superficial and deep retinal layers, as well as flow voids of the choriocapillaris.

Results: Twenty-eight eyes of 17 patients and 31 age-matched control eyes of 18 healthy subjects were included. VD and VSD of the deep retinal layer were significantly reduced in hypertensive crisis (P ≤ 0.004). Choriocapillaris signal intensity was more heterogeneous in patients, and flow voids exhibited confluence with a larger average area and a lower absolute count (P ≤ 0.045). These changes were independent of time since onset of hypertensive crisis and of the presence and extent of retinopathy. Deep retinal changes were associated with renal end-organ failure (P = 0.045).

Conclusions: Hypertensive crisis is associated with a significant reduction in retinal and choroidal capillary perfusion based on OCTA findings. These alterations are independent of retinopathy and related to end-organ damage.

Translational relevance: OCTA might help distinguish hypertensive urgency from hypertensive emergency earlier than currently possible.

Keywords: arterial hypertension; hypertensive crisis; optical coherence tomography angiography; perfusion; retina.

Conflict of interest statement

Disclosure: J.H. Terheyden, Heidelberg Engineering (F), Optos (F), Carl Zeiss Meditec (F), and CenterVue (F); M.W.M. Wintergerst, D-EYE (F), DigiSight Technologies (F), Heine Optotechnik (F), Heine Optotechnik GmbH (C); C. Pizarro, None; M. Pfau, Heidelberg Engineering (F), Optos (F), Carl Zeiss Meditec (F), and CenterVue (F), Carl Zeiss Meditec AG (C); G.N. Turski, Heidelberg Engineering (F), Optos (F), Carl Zeiss Meditec (F), and CenterVue (F); F.G. Holz, Heidelberg Engineering (F), Optos (F), Carl Zeiss Meditec (F), and CenterVue (F), Acucela (C), Bayer (C), Bioeg (C), Boehringer-Ingelheim (C), Genentech/Roche (C), Heidelberg Engineering (C), Novartis(C), Thea(C), Acucela (F), Allergan (F), Bayer (F), Bioeq (F), Genentech/Roche (F), Merz (F), NightstarX (F), Novartis (F), Allergan (R), Bayer (R), Carl Zeiss MediTec (R), Genentech/Roche (R), Heidelberg Engineering (R), Novartis (R); R.P. Finger, Heidelberg Engineering (F), Optos (F), Carl Zeiss Meditec (F), and CenterVue (F), Bayer (C), Novartis (C), Opthea (C), Novelion (C), Santhera (C), Inositec (C), Alimera (C), Ellex (C), Roche (C), RetinaImplant (C)

Copyright 2020 The Authors.

Figures

Figure 1.

Vessel density (a) and vessel skeleton density (b) values of the deep retinal layer in subjects with hypertensive crisis and controls with examples of binarized (a) and skeletonized (b) OCTA images. Values more than 1.5 times the interquartile range from the quartiles were considered outliers according to Tukey's rule.

Figure 2.

Boxplots showing choriocapillaris flow parameters in subjects with hypertensive crisis and controls (a, c, d, f, g, i), and exemplary raw (b) and binarized OCTA images of the choriocapillaris (e) with flow voids shown in black and the logarithmic choriocapillaris flow void distributions with regression lines (h) used to analyze slope and ordinate intercept. Values more than 1.5 times the interquartile range from the quartiles were considered outliers according to Tukey's rule.