Assessment of Cerebral Vasomotor Reactivity in Patients With Primary Open-angle Glaucoma and Ocular Hypertension Using the Breath-Holding Index

Abstract

Précis: Patients with ocular hypertension (OHT) do not show impaired cerebral vasodilation responses to hypercapnia but patients with primary open-angle glaucoma (POAG) do. Impaired vasoreactivity in patients with POAG may have neuronal or vascular origins and increase stroke risk. Purpose: To investigate changes in cerebral blood flow and cerebral vasomotor reactivity using the breath-holding index in patients with POAG and OHT, to examine whether these parameters contribute to the risk of ischemic stroke. Methods: Thirty patients with POAG, 30 patients with OHT, and 30 age- and sex-matched healthy control subjects were included in this university hospital-based, cross-sectional, and observational study. Eyes with a greater degree of visual field loss and/or more severe optic disc damage were selected for the study in patients with POAG, whereas in patients with OHT and controls, the study eye was chosen randomly. The mean blood flow velocity and breath-holding index were measured in the middle cerebral artery ipsilaterally in patient and control groups, by using transcranial Doppler ultrasonography. Results: The mean blood flow velocity and breath-holding indexes were significantly lower in patients with POAG than in the control group (all P<0.05). In the OHT group, the mean blood flow velocity and breath-holding indexes were not different from those in the control group. Conclusions: Patients with POAG have impaired vasodilation response to hypercapnia. Presumably, the neuronal changes and deterioration of the endothelium-mediated vasodilatation in patients with glaucoma may disrupt the regulation of arteries and potentially present functional insufficiency on vasoreactivity. Moreover, impaired cerebral vascular regulation may contribute to the increased risk of stroke in patients with POAG.

Prevalence and Risk Factors of Glaucoma Among Chinese People From the China Health and Retirement Longitudinal Study

“…6 Furthermore, glaucoma is the most common eye disease among people with valvular disease, anemia, and other diseases, and increased cardiovascular mortality has been observed in people with previously diagnosed glaucoma, probably due to the impaired vasodilation response to hypercapnia. [28][29][30] The Early Manifest Glaucoma Trial found that a history of cardiovascular disease is a significant predictor of glaucoma progression. 31 The inconsistency among these studies may be due to differences in the study design or the population characteristics.…”

“…In addition, a previous study speculated that the risk of glaucoma increases by 5% each year after a diagnosis of diabetes, and the association between diabetes and glaucoma could be because they share common mechanisms of vascular dysregulation 6. Furthermore, glaucoma is the most common eye disease among people with valvular disease, anemia, and other diseases, and increased cardiovascular mortality has been observed in people with previously diagnosed glaucoma, probably due to the impaired vasodilation response to hypercapnia 28–30. The Early Manifest Glaucoma Trial found that a history of cardiovascular disease is a significant predictor of glaucoma progression 31.…”

Arterial spin labeling reveals disordered cerebral perfusion and cerebral blood flow-based functional connectivity in primary open-angle glaucoma

“…The ophthalmic artery, middle cerebral artery and posterior cerebral artery, which account for most of the blood supply to the orbit and visual cortex, show reduced blood ow velocities in patients with POAG as measured by transcranial Doppler (Arslan et al, 2021;Harris et al, 2013). Studies conducted by three-dimensional pseudo-continuous arterial spin labeling (3D-pCASL) have demonstrated reduced resting cerebral blood ow (CBF) and reduced visual evoked CBF in the visual cortex in patients with POAG (Wang et al, 2018;Zhang et al, 2015).…”

Arterial spin labeling reveals disordered cerebral perfusion and cerebral blood flow-based functional connectivity in primary open-angle glaucoma

“…The ophthalmic artery, middle cerebral artery and posterior cerebral artery, which account for most of the blood supply to the orbit and visual cortex, show reduced blood flow velocities in patients with POAG as measured by transcranial Doppler (Arslan et al, 2021 ; Harris et al, 2013 ). Studies conducted by three-dimensional pseudo-continuous arterial spin labeling (3D-pCASL) have demonstrated reduced resting cerebral blood flow (CBF) and reduced visual evoked CBF in the visual cortex in patients with POAG (Wang et al, 2018 ; Zhang et al, 2015 ).…”