Application Value of Optical Coherence Tomography to Detect Neuronal Damage in Hypertensive Retinopathy

Abstract

Background The current prevalence of hypertension is increasing year by year, and its ocular complication, hypertensive retinopathy, is also receiving increasing attention. However, little attention has been paid to neuronal damage in hypertensive retinopathy. Objective To investigate the application and value of optical coherence tomography as a screening tool in the evaluation of neuronal damage in hypertensive retinopathy. Methods A total of 102 patients with hypertension who were admitted to Hospital Clínico Quirúrgico "Hermanos Ameijeiras" (HHA Hospital) from March 2019 to July 2020 were included as study subjects, as well as 45 healthy subjects as the control group to monitor 24-h ambulatory blood pressure. The average arterial blood pressure of 24-h diastolic and systolic blood pressure were taken, intraocular pressure (IOP) was measured and ocular perfusion pressure was calculated. The thickness of retinal nerve fiber layer (RNFL) and ganglion cell complex layer (GCC) in macular region were measured. The patients were divided into the control group (n=51) and uncontrolled group (n=51) according to their blood pressure control, with 45 healthy subjects as the control group. Pearson correlation analysis or Spearman rank correlation analysis were used to explore the correlation of blood pressure, ocular perfusion pressure, retinopathy and GCC thickness with blood pressure, as well as ocular perfusion pressure with retinopathy, and mediation analysis was performed using R 3.5.3 software. Results There were significant differences in race, systolic blood pressure, diastolic blood pressure, average arterial pressure, IOP, ocular perfusion pressure and retinopathy among the three groups (P<0.05) . The average RNFL thickness in the uncontrolled blood pressure group was lower than that in the control group (P<0.05) , the average GCC thickness in the control group and uncontrolled blood pressure group was lower than that in the control group, and the minimum GCC thickness in the uncontrolled blood pressure group was lower than that in the control group (P<0.05) . Correlation analysis results showed that average GCC thickness, superior temporal GCC thickness and inferior temporal CCG thickness were negatively correlated with systolic blood pressure, diastolic blood pressure, ocular perfusion pressure and retinopathy (P<0.05) , while superior temporal GCC thickness was negatively correlated with systolic blood pressure, diastolic blood pressure and ocular perfusion pressure (P<0.05) ; inferior temporal CCG thickness was negatively correlated with diastolic blood pressure (P<0.05) , retinopathy was positively correlated with systolic blood pressure, diastolic blood pressure and ocular perfusion pressure (P<0.05) . The mediating effect showed a significant effect of "systolic blood pressure→average GCC thickness→hypertensive retinopathy" , with systolic blood pressure positively correlated with average GCC thickness, average GCC thickness positively correlated with hypertensive retinopathy (P<0.05) . Systolic blood pressure had a direct effect on the risk of hypertensive retinopathy (β=0.013, 95%CI=0.007-0.020, P<0.001) , and the average GCC thickness partially mediated the effect of systolic blood pressure on the risk of hypertensive retinopathy (β=0.117, 95%CI=0.014-0.360, P=0.04) , the mediating effect accounted for 11.7% of the total effect. Conclusion Optical coherence tomography is a non-invasive ophthalmological test that can detect hypertensive retinal neuronal damage superior to normal fundus examination, provide early prevention and warning of irreversible blindness and hypertensive target organ damage in hypertension-induced optic neuronal damage.

Keywords

• hypertensive retinopathy|hypertension|optical coherence tomography|nervefibers|mediation analysis