Quantification of blood-aqueous barrier function using laser flare measurement and fluorophotometry--a comparative...

Area of Science:

• Ophthalmology
• Ocular Physiology
• Biomedical Optics

Background:

• The blood-aqueous barrier (BAB) regulates the passage of substances into the anterior chamber.
• Fluorophotometry and laser flare photometry are non-invasive techniques to assess BAB integrity.
• Understanding the relationship between these methods is crucial for diagnosing ocular inflammatory conditions.

Purpose of the Study:

• To investigate the quantitative relationship between fluorescein permeability coefficient (k(a)) measured by fluorophotometry and laser flare photometry.
• To determine if laser flare photometry measurements are affected during fluorophotometry procedures.
• To assess the reproducibility of both measurement techniques.

Main Methods:

• Laser flare measurements were performed on 40 eyes before and during fluorophotometry.
• Fluorophotometry was used to calculate the permeability coefficient k(a) of the BAB to fluorescein.
• Eyes ranged from healthy to mild uveitis.

Main Results:

• A significant exponential correlation (r = 0.8; p = 0.05) was found between laser flare count and fluorescein permeability coefficient k(a).
• Laser flare counts did not significantly increase during the fluorophotometry procedure.
• Reproducibility was acceptable for both laser flare measurements (14% ± 7.5%) and fluorophotometry (13% ± 5%).

Conclusions:

• The exponential relationship suggests fluorophotometry is more sensitive for detecting early BAB dysfunction.
• Laser flare photometry may be more suitable for assessing more severe cases of BAB dysfunction.
• BAB malfunction may differentially affect permeability to high and low molecular weight molecules.