Abstract
PURPOSE: To assess vascular endothelial function in patients with normal pressure glaucoma using forearm blood flow responses to intra-arterial infusions of endothelial-dependent and -independent vasoactive agents.
METHODS: Eight patients with newly diagnosed and untreated normal pressure glaucoma and eight healthy age- and sex-matched control volunteers underwent measurement of forearm blood flow using venous occlusion plethysmography. Blood flow was assessed in response to incremental doses of sodium nitroprusside (an endothelial-independent vasodilator), acetylcholine (an endothelial-dependent vasodilator) and the vasoconstrictor N(G)-monomethyl-L-arginine (an inhibitor of nitric oxide synthase).
RESULTS: Sodium nitroprusside caused a dose-related increase in forearm blood flow in patients and controls. Glaucoma patients appeared to have an increased vasodilatory response, but this was not significant (P = 0.23). Acetylcholine also induced vasodilatation in both groups, but the response was significantly reduced in the glaucoma group (P = 0.04). N(G)-monomethyl-L-arginine induced a similar degree of vasoconstriction in both groups (P = 0.76).
CONCLUSIONS: This study has shown an impairment of peripheral endothelium-mediated vasodilatation in normal pressure glaucoma. These findings would support the concept of a generalized vascular endothelial dysfunction in patients with this condition.
Original language | English |
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Pages (from-to) | 1710-4 |
Number of pages | 5 |
Journal | Investigative Ophthalmology & Visual Science (IOVS) |
Volume | 40 |
Issue number | 8 |
Publication status | Published - Jul 1999 |
Keywords / Materials (for Non-textual outputs)
- Acetylcholine
- Blood Flow Velocity
- Brachial Artery
- Dose-Response Relationship, Drug
- Endothelium, Vascular
- Enzyme Inhibitors
- Female
- Forearm
- Glaucoma, Open-Angle
- Humans
- Infusions, Intra-Arterial
- Intraocular Pressure
- Male
- Middle Aged
- Nitric Oxide Synthase
- Nitroprusside
- Plethysmography
- Vasodilator Agents
- omega-N-Methylarginine