ANTERIOR-CHAMBER FLUORESCEIN KINETICS COMPARED WITH VITREOUS KINETICSIN NORMAL SUBJECTS

Purpose: Describe and compare barrier properties in various parts of t he eye. Methods: Fluorophotometric measurements of the anterior chambe r, vitreous and plasma fluorescein concentrations were performed and s ubjected to a kinetic two-compartment analysis. Results: The overall b arrier properties as revealed by a permeability-index was found to be 12.2% (anterior chamber) and 3.5% (vitreous), The apparent rate consta nt of permeation into the anterior chamber (K-in=1,59 h(-1)) was found to be significantly higher than into the vitreous (K-in=0,66 h(-1)) a nd into the apparent peripheral body compartment (K-in=0,23 h(-1)). Th e terminal rate constant of fluorescein disposition from the anterior chamber (K-out=0,21 h(-1)) was in agreement with the terminal disposit ion rate constant for plasma fluorescein (beta=0,23 h(-1)), whereas el imination from the vitreous (K-out=0,072 h(-1)) was significantly slow er. Conclusion: Compartment analysis of ocular fluorescein kinetics is suitable for the study of anterior and posterior barrier properties i n the eye, In this study fluorescein elimination from the anterior cha mber was restricted by terminal plasma fluorescein decay rather than b y ocular tissue.