Experimental retinal detachment. VI. The permeability of the blood-retinal barrier

Fluorophotometry was used to study the permeability of the blood-retinal barrier in six monkeys with stable rhegmatogenous retinal detachments. Fluorescein transport was inhibited by probenecid. The rate of fluorescein disappearance (KvVv) was determined following intravitreal injection. In a separate experiment the equilibrium vitreous-plasma concentration ratio (Cv/Cp) was determined following intraperitoneal administration. Expressed in equivalent volumes of vitreous, the rate of fluorescein diffusion across the blood-retinal barrier (K'vVvCv/Cp) was 0.29 microL/min in control eyes and 0.73 microL/min in detached eyes. The rate of fluid movement across the blood-retinal barrier (K'vVv) [1 - (Cv/Cp)] was 2.89 microL/min in control eyes and 6.38 microL/min in detached eyes. Posterior movement of fluid contributes to retinal apposition under normal conditions and accounts for the rapid resolution of retinal detachment following closure of the retinal hole.