Detection of Retinal Neurovascular Coupling During Light Adaptation Using Optical Coherence Tomography Angiography: A...

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Neurovascular coupling (NVC) links retinal blood flow to metabolic demand.
• Dynamic vessel analysis (DVA) assesses NVC with flicker stimulation.
• OCTA's potential for NVC assessment during physiological stimuli like light adaptation is unexplored.

Purpose of the Study:

• To investigate OCTA's capability in detecting NVC during dark-to-light adaptation.
• To quantify changes in retinal vessel density (VD) using OCTA under scotopic and photopic conditions.

Main Methods:

• Prospective cross-sectional study involving 22 healthy participants.
• OCTA imaging performed under dark-adapted and light-adapted conditions, with repeated measurements.
• Quantification of macular and peripapillary vessel density (VD).

Main Results:

• Light adaptation significantly increased peripapillary small VD (+1.30%, p=0.046).
• A trend for increased peripapillary all VD was observed (p=0.069).
• Macular VD showed no significant change, but was influenced by scan quality (p<0.001).

Conclusions:

• OCTA detected increased peripapillary VD with light adaptation in healthy older adults, indicating retinal vascular reactivity consistent with NVC.
• Scan quality and measurement order are critical confounding factors for functional OCTA studies.
• OCTA shows promise for assessing retinal neurovascular reactivity, emphasizing the need for standardization and correction.