Evaluation of microvascular changes in the macula and optic nerve head in patients with systemic hypertension without hypertensive retinopathy

Introduction: In our study, microvascular changes in the macula and optic nerve head as a result of arteriolar narrowing and vasoconstriction caused by hypertension in systemic hypertension patients without hypertensive retinopathy were examined by optical coherence tomography angiography imaging method. Methods: In our study, 100 eyes of 100 patients with systemic hypertension and without hypertensive retinopathy were included in the study group and 50 eyes of 50 patients without any systemic or ocular disease were included in the control group. Best corrected visual acuity and complete ophthalmologic examinations of the patients and control group were recorded. Blood pressure values and estimated glomerular filtration rates (eGFR) of all subjects included in the study were measured. Enhanced depth imaging with optical coherence tomography subfoveal choroidal thickness, optical coherence tomography angiography with retinal thickness (μm), foveal avascular zone (mm2), capillary density around the foveal avascular zone (FAZ FD, %), perimeter of the foveal avascular zone (mm), vascular density (%) in the superficial and deep capillary plexus,, choriocapillary flow area and non-flow area in the superficial capillary plexus, retinal nerve fiber layer thickness (mm) at the optic nerve head and vascular density, cup-disk (C/D) ratio were measured and recorded. All parameters were compared between the hypertensive group and the control group, and microvascular changes in the macula and optic nerve head were analyzed in patients with systemic hypertension without hypertensive retinopathy. Results: In our study, retinal thickness of patients with hypertension over 10 years and without hypertensive retinopathy was found to be significantly thinner than patients with hypertension under 10 years and the control group. There was no significant difference in superficial and deep capillary plexus vessel densities, FAZ, FAZ perimeter and FAZ FD values, choriocapillary flow area and non-flow area measurements in the superficial capillary plexus between hypertensive patients and the control group. Subfoveal choroidal thickness was found to be significantly thinner in patients with hypertension for more than 10 years. There was no significant difference in the measurements of retinal nerve fiber layer thickness, inside disc and peripapillary capillary density, C/D ratio in hypertension patients compared to the control group. The eGFR level was found to be significantly lower in patients with hypertension Conclusion: By examining the microvascular changes in the macula and optic nerve head of systemic hypertension patients with optical coherence tomography angiography, the damage caused by hypertension can be detected early, the follow-up of the disease and the response to the treatment can be monitored.