Retinal blood flow in eyes with primary open-angle glaucoma using a new Adaptive Optics Laser Doppler Velocimeter...

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Understanding the role of hemodynamics in glaucoma pathogenesis is crucial for early detection and treatment.
• Current methods for assessing retinal blood flow (RBF) in glaucoma require further refinement.

Purpose of the Study:

• To quantify RBF in the retinal veins of POAG patients using a prototype Adaptive Optics Laser Doppler Velocimeter (AO-LDV).
• To compare RBF measurements between POAG patients and healthy controls.
• To investigate potential correlations between RBF, visual field (VF) loss, and retinal nerve-fiber layer (RNFL) thickness in POAG.

Main Methods:

• A prospective study involving 12 POAG patients and 11 healthy controls.
• Utilized a prototype AO-LDV system, integrating a laser Doppler velocimeter with an adaptive optic fundus camera, to measure blood vessel diameter and flow.
• Assessed RBF in the superior temporal vein (STV) and inferior temporal vein (ITV), alongside VF testing and RNFL thickness measurements via OCT.

Main Results:

• A trend towards lower STV velocity was observed in the POAG group (6.30 ± 1.6 mm/s) compared to controls (8.6 ± 2.8 mm/s, p=0.07).
• No significant differences in ITV velocity or STV/ITV diameters were found between groups.
• No significant correlations were identified between RBF in STV or ITV and VF loss or RNFL thickness.

Conclusions:

• The prototype AO-LDV system demonstrated capability for accurate RBF measurement in glaucoma patients.
• Preliminary findings suggest that RBF is not significantly reduced in early to moderate stages of POAG.
• Further validation in larger cohorts, particularly with late-stage glaucoma, is recommended to confirm these results.