Retinal Microvascular Change in Hypertension as measured by Optical Coherence Tomography Angiography

Many studies have reported the effect of hypertension on microcirculation of the retina. Advance of optical coherence tomography angiography (OCTA) allows us more detailed observations of microcirculation of the retina. Therefore, we compared OCTA parameters between chronic hypertension (disease duration of at least 10 yrs; Group A, 45 eyes), relieved hypertensive retinopathy (grade IV HTNR < 1 yr prior; Group B, 40 eyes), and normal controls [Group C (50 eyes) >= 50 yrs old and Group D (50 eyes) < 50 yrs old]. A 3 x 3 mm macular scan was performed in each group by OCTA. In vessel density of 3 mm full, group A and B were significantly decreased compared to normal control group (Group A vs. C; 19.4 mm(-1) vs. 20.1 mm(-1), Group B vs. D; 19.8 mm(-1) vs. 21.8 mm(-1), all p < 0.05). In foveal avascular zone, group A and B were significantly increased compared to normal control group (Group A vs. C; 0.35 mm(2) vs. 0.30 mm(2), Group B vs. D; 0.36 mm(2) vs. 0.29 mm(2), all p < 0.05). OCTA is useful for examining retinal microcirculatory changes in hypertension and we confirmed that hypertension affects the OCTA parameters. Considering the effect of hypertension on the change of microvasculature, care is required in the interpretation of OCTA parameters in various ophthalmic condition.