Early changes of retinal and choroidal microvascular structure in hypertensive patients

AIM: To explore the feasibility of swept source optical coherence tomography angiography(SS-OCTA)in evaluating early retinal and choroidal microcirculation changes in patients with hypertension.METHODS:Prospective clinical study. A total of 27 patients with grade 2 or 3 essential hypertension(hypertension group)diagnosed in the Department of Cardiology of Xi'an First Hospital from July to November 2022 were included in the study. There were 14 males and 13 females. The mean age was(57.11±3.36)years. During the same period, 27 age- and sex-matched normal people without a history of hypertension were selected as the control group, including 12 males and 15 females. The average age was(55.74±2.95)years old. All patients underwent BCVA(LogMAR), intraocular pressure, axial length, slit lamp examination, fundus color photography and SS-OCTA examination. SS-OCTA was used to scan the macular area of the right eye in the range of 6×6 mm. The retina and choroid were divided into three concentric circles with diameters of 0-1 mm, 1-3 mm and 3-6 mm around the fovea according to ETDRS. Macular vessel density(VD), perfusion area(PA), retinal thickness(CMT), choroidal thickness(CT), choroidal vessel volume(CVV)and choroidal vasculr index(CVI)of the superficial capillary plexus(SCP)and the deep capillary plexus(DCP)in the macular area of 0-1 mm, 1-3 mm and 3-6 mm were analyzed and recorded. The changes in VD, PA, CMT, CT, CVV and CVI were compared between the two groups. Independent sample t-test was used to compare VD, PA, CMT and CVI between the two groups; CT, CVV and LogMAR visual acuity were analyzed by Wilcoxon signed rank test of independent samples.RESULTS:Compared with the control group, the hypertensive group had significantly lower VD in the macular area 0-3 mm(0-1 mm, t=-3.144; 1-3 mm, t=-3.611, P0.05). The CMT in the 0-1mm area of the macular area in the hypertension group was lower than that in the control group(t=-2.624, P0.05).CONCLUSION:The VD of DCP in the 0-3 mm area and the CMT in the 0-1 mm area are decreased in hypertensive patients. There were no significant differences in CT, CVV and CVI between the two groups. VD and CMT in macular DCP may be used as indicators to evaluate the early changes of retinal and choroidal microcirculation in hypertensive patients.