A Pilot Study Assessing Retinal Blood Flow Dysregulation in Glaucoma Using Erythrocyte Mediated Velocimetry

Area of Science:

• Ophthalmology
• Cardiovascular Physiology
• Medical Diagnostics

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Retinal blood flow dysregulation is implicated in glaucoma pathogenesis.
• Understanding autoregulation is crucial for diagnosing and managing glaucoma.

Purpose of the Study:

• To compare retinal arteriolar and venular blood flow autoregulation in glaucoma, glaucoma suspect, and control participants.
• To utilize erythrocyte mediated velocimetry for precise blood flow measurements.
• To investigate the impact of hyperoxia on retinal blood flow dynamics.

Main Methods:

• Prospective cohort pilot study involving 19 participants (glaucoma, glaucoma suspect, controls).
• Erythrocyte velocity measured in retinal arterioles and venules using erythrocyte mediated velocimetry.
• Velocity changes assessed under room air and oxygen supplementation (hyperoxia).

Main Results:

• No significant difference in baseline velocities among groups.
• Hyperoxia decreased mean arterial erythrocyte velocity in glaucoma patients (-7.2%).
• Hyperoxia increased erythrocyte velocity in controls (4.6%) and glaucoma suspects (7.2%).
• Glaucoma diagnosis, higher baseline arteriolar velocity, and White race were associated with decreased velocity under hyperoxia.

Conclusions:

• Glaucoma patients exhibit impaired retinal blood flow autoregulation during hyperoxia.
• Erythrocyte velocity response to hyperoxia may serve as a biomarker for glaucoma.
• Further research can leverage these findings for glaucoma diagnosis and treatment development.