Morphology of the breakdown of the blood-aqueous barrier in the ciliary processes of the rabbit eye after prostaglandin E2.

Protaglandin E2, administered topically to the rabbit eye, causes disruption of the blood-aqueous barrier resulting in a large increase in the protein content of the aqueous humor. The route of plasma proteins into the aqueous humor was studied with the electron microscope, using horseradish peroxidase as a protein tracer. The tracer penetrated the tight junctions of the nonpigmented layer of the ciliary epithelium, filling the lateral intercellular clefts and staining the internal limiting membrane. These morphological studies confirm the prior physiologic demonstration that, in response to prostaglandin, plasma proteins enter the posterior chamber via the intercellular clefts of the nonpigmented epithelium.