Human ocular surface microcirculation quantified by in vivo computer assisted video microscopy and diffuse...

Area of Science:

• Ophthalmology
• Microvascular Physiology
• Biomedical Imaging

Background:

• Non-invasive imaging is crucial for quantifying anterior segment ocular structures.
• Assessing ocular surface microvascular function is vital for understanding eye health.
• The oxygen delivery index (ODIN) is a novel concept for quantifying microvascular oxygen delivery capacity.

Purpose of the Study:

• To test the applicability of technologies for acquiring ocular surface data in humans.
• To validate the sensitivity of the ODIN concept in differentiating microvascular structure and function.
• To compare microvascular parameters between the limbal and bulbar conjunctiva.

Main Methods:

• Applied the oxygen delivery index (ODIN) concept to the human ocular surface.
• Utilized computer-assisted video microscopy and diffuse reflectance spectroscopy for measurements.
• Acquired data from limbal and bulbar conjunctiva in 20 healthy volunteers.

Main Results:

• Functional capillary density was significantly higher in the limbus (11.2 c/mm) compared to bulbar conjunctiva (5.2 c/mm).
• Microvascular oxygen saturation was lower in the limbus (77%) versus bulbar conjunctiva (89%).
• Over 80% of capillaries exhibited continuous blood flow, with no significant difference between sites.

Conclusions:

• The ODIN concept is applicable for assessing human ocular surface microvascular function.
• ODIN demonstrates sufficient sensitivity to detect differences in capillary density and oxygen extraction.
• The study successfully differentiated microvascular function between limbal and bulbar conjunctiva.