The Role of Color Doppler Imaging in the Diagnosis of Glaucoma: A Review of the Literature

Abstract

Glaucoma is a progressive optic neuropathy and one of the leading causes of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the major risk factor for the onset and progression of glaucoma. In addition to elevated IOP, impaired intraocular blood flow is also considered to be involved in the pathogenesis of glaucoma. Various techniques have been used to assess ocular blood flow (OBF), including Color Doppler Imaging (CDI), a technique used in ophthalmology in recent decades. This article reviews the role of CDI in both the diagnosis and effective monitoring of glaucoma progression, presenting the protocol for imaging and its advantages, as well as the limitations of its use. Moreover, it analyzes the pathophysiology of glaucoma, focusing on vascular theory and its role in the onset and progression of the disease.

Cardiac Surgery Patients Have Reduced Vascularity and Structural Defects of the Retina Similar to Persons with Open-Angle Glaucoma

“…In this study, we investigated systemic and ocular vascular parameters assessed via multi-modal imaging modalities including OCT, OCT-A, and CDI in OAG patients compared to CS patients and healthy controls. Several studies previously showed reduced PSV and EDV and increased RI in the retrobulbar vessels of OAG patients compared to healthy controls [ 21 , 22 , 23 ]. CDI has been suggested as a valuable tool to assess ocular blood flow and assist in diagnosis and progression monitoring [ 22 , 23 ].…”

“…Several studies previously showed reduced PSV and EDV and increased RI in the retrobulbar vessels of OAG patients compared to healthy controls [ 21 , 22 , 23 ]. CDI has been suggested as a valuable tool to assess ocular blood flow and assist in diagnosis and progression monitoring [ 22 , 23 ]. In our study, the retrobulbar blood flow parameters did not significantly differ between OAG patients and healthy controls.…”

“…Both the OAG and CS patients presented significantly higher VD in the central region of the ONH choriocapillaris layer. These findings may be related to capillary dilation in response to BP or OPP fluctuations, since the choroidal circulation does not have vascular autoregulation but has a neurogenic control [ 22 ]. In agreement with our study, Khayrallah et al and Yospon et al found positive correlations between ONH VD and RNFL thickness in OAG patients, thus suggesting that impaired retinal and ONH microcirculation is associated with nervous tissue thinning [ 31 , 32 ].…”

Glaucoma Surgery and Ocular Blood Flow in Colour Doppler Imaging: Is There a Link?

“…An additional parameter determined during the examination is the pulsatility index. The pulsatility index is used to evaluate vessels in which retrograde flow can occur and is obtained using the following formula: 10 …”

Current State of Knowledge in Ocular Blood Flow in Glaucoma: A Narrative Review

“… 13 CDI, with no ionizing radiation exposure and economic and easy accessibility, has been reported as a useful approach for diagnosing and monitoring glaucoma cases. 14 Although CDI is an effective method for assessing large arteries, it does not provide quantitative information on the vessel diameter. This technique cannot measure vessel diameter; thus, volumetric blood flow calculations are not possible.…”