Anterior chamber and vitreous fluorescein kinetics in normal and diabetic subjects

Purpose: Describe and compare drug exchange between various parts of the eye. Methods: Fluorophotometric measurements of the anterior chamber, vitreous and plasma fluorescein concentrations were performed and subjected to a kinetic two-compartment analysis. Results: The overall barrier properties as revealed by a permeability-index were found to be 12.2% and 3.5% for the anterior chamber and the vitreous, respectively. The apparent rate constant of permeation into the anterior chamber was found to be significantly higher than into the vitreous and the apparent peripheral body compartment, The terminal rate constant of fluorescein disposition from the anterior chamber was in agreement with the terminal disposition rate constant for plasma fluorescein, whereas elimination from the vitreous was significantly slower, Conclusion: Compartment analysis of ocular fluorescein kinetics is suitable for the study of anterior and posterior barrier properties in the eye. In this study fluorescein elimination from the anterior chamber was restricted by terminal plasma fluorescein decay rather than by ocular tissue.