Correlation of Measurements From Doppler Ultrasound and Optical Coherence Tomography in Glaucoma

Abstract

Objectives To relate the changes in ocular structure and hemodynamic response in primary open‐angle glaucoma (POAG). Methods Patients with POAG (n = 46) and control subjects (n = 53) were recruited. Retinal nerve fiber layer and ganglion cell complex were evaluated using optical coherence tomography (OCT). Blood flow was characterized in ophthalmic artery (OA) and central retinal artery (CRA) using color Doppler ultrasonography (CDU), and resistivity index (RI) was calculated. Measurements from CDU and OCT were statistically correlated and the degree of the association was examined. Receiver operating characteristics was produced based on RI and optimal threshold was determined. Results In POAG patients, OCT revealed neuronal damage and CDU indicated increased resistance to arterial flow. Flow dynamics correlated negatively with the ocular tissue dimensions, sufficiently establishing an association between the ocular structure and its hemodynamic response. Based on the possibility of indirect POAG diagnosis with CDU, threshold 0.7 for RI of OA yielded 73.9% sensitivity and 77.4% specificity in distinguishing the cases of POAG from the controls. Threshold of 0.66 for RI of CRA, had higher specificity of 83%, but lower sensitivity of 52.1%. Conclusions Ocular flow exhibits different characteristics in individuals with POAG than normal. The changes associated with the underlying neuronal structure, suggesting the possibility of a potential new diagnostic biomarker for POAG. This justifies further studies with a larger cohort, examining the ocular flow with CDU in POAG and comparing it against OCT findings for establishing the power of CDU in differential diagnosis or glaucoma progression.

Analysis of the Optic Nerve Head Microcirculation Using Optical Coherence Tomography Angiography and the Upstream Macrocirculation Using Color Doppler Imaging in Low-Tension and High-Tension Glaucoma Patients

“…CDI estimates the blood flow in large vessels using the blood velocity rather than the actual blood flow [34, 44]. CDI is commonly used to monitor the large vessels, such as the ICA, OA, CRA, and SPCA [30].…”

“…Glaucoma patients had lower EDV and higher RI in the OA, SPCA, and CRA compared with healthy controls [34]. Similarly, in another study, POAG patients had a higher RI in the OA compared with healthy controls [44]. Patients with LTG or POAG had significantly higher pulsatility index and RI of the OA and significantly lower peak ratio and EDV compared with healthy controls [49].…”