Pharmacokinetics of fluorescein in the vitreous.

The pharmacokinetics of fluorescein in the vitreous after intravenous or oral fluorescein administration was studied in normal individuals. Vitreous and free blood fluorescein concentrations were measured over an 8 hr period by fluorophotometry and fluorescence polarization. A computer model was constructed based on the free plasma fluorescein concentrations and conformed closely to the experimental data. The concentration profiles of fluorescein appearance in the vitreous were then examined. The effect of alterations in retinal permeability and free blood fluorescein concentration are also discussed. This article illustrates that an increase in the concentration of fluorescein in the vitreous as measured by fluorophotometry can be caused by factors other than an increase in blood-retinal barrier permeability.