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09:03
Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye
Published on: June 20, 2015
The hemorheological mechanisms in normal tension glaucoma
Huey-Chuan Cheng1, Chi-Ming Chan, Shu-I Yeh
1Department of Ophthalmology, Mackay Memorial Hospital, Taipei, Taiwan.
Current Eye Research
|May 26, 2011
Summary
Patients with normal tension glaucoma (NTG) exhibit significantly higher blood viscosity and impaired erythrocyte function compared to healthy individuals. These hemorheological changes may contribute to optic nerve hypoperfusion in NTG.
Area of Science:
- Ophthalmology
- Hematology
- Biophysics
Background:
- Normal tension glaucoma (NTG) is a form of glaucoma where intraocular pressure is not elevated.
- Understanding the underlying pathophysiology of NTG is crucial for developing effective treatments.
Purpose of the Study:
- To investigate and compare hemorheological parameters between patients diagnosed with normal tension glaucoma (NTG) and age-matched healthy controls.
- To identify potential blood flow-related abnormalities contributing to NTG pathogenesis.
Main Methods:
- Twenty patients with NTG and 21 healthy controls were enrolled.
- Blood viscosity, erythrocyte deformability, erythrocyte aggregation, and blood oxygen transport efficiency were measured.
- Measurements utilized rotational rheometry and ektacytometry on venous blood samples.
Main Results:
- NTG patients demonstrated significantly higher blood viscosity across all tested shear rates (high, medium, low).
- Erythrocyte aggregation index was significantly higher, while erythrocyte deformability was significantly lower in the NTG group.
- Blood's oxygen transport efficiency was notably reduced in NTG patients at all shear rates.
Conclusions:
- Elevated blood viscosity in NTG may stem from reduced erythrocyte deformability and altered erythrocyte rigidity.
- Increased erythrocyte aggregability contributes to higher blood viscoelasticity and viscosity at low shear rates in NTG.
- Impaired erythrocyte deformability and reduced oxygen transport efficiency in NTG patients may lead to optic nerve hypoperfusion.
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