Central Retinal and Ophthalmic Artery Doppler Velocimetry among Hypertensives and Normotensive Adults at a Nigerian Tertiary Health Facility

Abstract

Background: Haemodynamic alterations of the retrobulbar circulation are sequelae of untreated, long-standing hypertension. Early evaluation of the retrobulbar blood flow is very crucial to prevent irreversible ocular complications. The objective of this study was to evaluate the differences in central retinal artery (CRA) and ophthalmic artery (OA) haemodynamics in adult hypertensive and non-hypertensive subjects.

Methodology: This prospective, comparative cross-sectional study was conducted among 63 hypertensives and 75 normotensive controls. Using Doppler ultrasonography, the CRA and OA Doppler velocimetry parameters among cases and controls were evaluated and analysed.

Results: The CRA Peak Systolic Velocity (PSV) and End-diastolic velocity (EDV) was 7.54 ± 2.60cm/s and 2.99 ± 1.15cm/s (p<0.001) in hypertensives but 10.8 ± 2.51cm/s and 4.50 ± 1.25cm/s) p<0.001 in controls. The systolic/diastolic ratio (S/D) in cases was 2.64 ± 0.75 and 2.44 ± 0.38 p=0.045 in controls. The CRA's Pulsatility Index (PI) between cases and controls was not statistically significant, p =0.082. Furthermore, the CRA's PSV, PI, Resistivity index (RI) and S/D, were higher among subjects with stage 1 compared to stage 2 hypertension (p=0.004; p=0.027; p<0.001 and p=0.001 respectively). The OA mean EDV in hypertensives was 4.57 ± 1.97 and in controls= 5.31 ± 1.79 (p=0.022), while the OA mean RI and Peak Ratio, p=0.009 and 0.003, respectively, were higher in stage 1 hypertension.

Conclusion: The Central retinal and ophthalmic artery blood flow parameters were significantly lower among hypertensive cases. Also, hypertensive stage 2 cases had significantly lower blood flow and vascular impedance parameters in the CRA and both Central retinal and ophthalmic artery, respectively.