Monitoring the haemodynamic response to visual stimulation in glaucoma patients

Area of Science:

• Neuroscience
• Ophthalmology
• Biomedical Engineering

Background:

• Glaucoma is a progressive optic neuropathy often associated with altered cerebral blood flow.
• Accurate assessment of hemodynamic changes in glaucoma is crucial for early diagnosis and management.
• Current diagnostic methods may not fully capture the subtle hemodynamic alterations in glaucoma.

Purpose of the Study:

• To evaluate the hemodynamic response function (HRF) in the occipital cortex of glaucomatous eyes compared to healthy eyes using TD-fNIRS.
• To assess the diagnostic potential of TD-fNIRS parameters in differentiating between healthy and glaucomatous eyes.
• To investigate the association between HRF parameters (amplitude and latency) and glaucoma pathology.

Main Methods:

• Utilized time-domain functional near-infrared spectroscopy (TD-fNIRS) to measure hemodynamic responses.
• Enrolled 98 subjects, classified as healthy, glaucoma patients (primary open-angle glaucoma), or mixed.
• Analyzed HRF amplitudes and latencies of oxygenated and deoxygenated hemoglobin following visual stimulation in 73 healthy and 62 glaucomatous eyes.

Main Results:

• Significant association found between HRF amplitudes (oxygenated and deoxygenated hemoglobin) and glaucoma pathology.
• HRF amplitudes demonstrated significant discriminating ability between healthy and glaucomatous eyes.
• No significant differences were observed in the latencies of hemodynamic parameters related to glaucoma.

Conclusions:

• TD-fNIRS is a promising noninvasive tool for evaluating hemodynamic alterations in glaucoma.
• HRF amplitude changes are significant indicators of glaucoma pathology.
• The ease of use and noninvasiveness of TD-fNIRS support its role as an adjunctive diagnostic tool in glaucoma evaluation.