Morphological changes in and quantitative analysis of macular retinal microvasculature by optical coherence tomography angiography in hypertensive retinopathy.

Hypertension is a serious global health problem. Hypertensive retinopathy is generally considered to be a predictor of vascular disease elsewhere in the human body. In the past few decades, a variety of grading systems have been proposed for hypertensive retinopathy. However, these grading systems have some limitations. This study utilized optical coherence tomography angiography (OCTA) to investigate the morphological changes and macular retinal microvasculature in depth among 100 patients with hypertensive retinopathy and 66 healthy participants. Five main pathological changes were discovered in hypertensive retinopathy, as follows: focal capillary sparsity, scattered microangioma, focal macular arch ring defects, focal capillary disorder, and focal capillary nonperfusion at the levels of the superficial and deep vascular networks. In addition, we have found that the number of various pathological changes shows an increasing trend as hypertensive retinopathy progresses and may be related to renal damage. Finally, deep vessel density tended to decrease with progressive stages of hypertensive retinopathy and could be the best indicator to predict the risk of hypertensive retinopathy. Our study, therefore, proposes 3 stages of hypertensive retinopathy without macular edema according to the pathophysiology found by OCTA: stage 1 (only focal capillary sparsity), taking the place of KWB grade I; stage 2 (focal capillary sparsity and scattered microangioma), taking the place of KWB grade II; and stage 3 (focal capillary sparsity, scattered microangioma, focal capillary disorder, and nonperfusion), taking the place of KWB grade III. Hence, OCTA may be a potentially useful tool for evaluating the pathophysiology and staging of hypertensive retinopathy. Further longitudinal prospective studies are needed to confirm our findings.