Inflammation can break down this barrier allowing drugs and large molecules to penetrate into the eye.
As the inflammation subsides, this barrier usually returns.
It consists of the following components:
- Blood–aqueous barrier: the ciliary epithelium and capillaries of the iris. Blood-aqueous barrier is formed by nonpigmented ciliary epithelial cells of the ciliary body and endothelial cells of blood vessels in the iris.
- Blood–retinal barrier: non-fenestrated capillaries of the retinal circulation and tight-junctions between retinal epithelial cells preventing passage of large molecules from choriocapillaris into the retina. Formed by endothelium of retinal vessels and epithelium of retinal pigment.
- Blood–air barrier – Membrane separating alveolar air from blood in lung capillaries
- Blood–brain barrier – Semipermeable capillary border that allows selective passage of blood constituents into the brain
- Blood–retinal barrier – Part of the blood–ocular barrier that prevents certain substances from entering the retina
- Blood–testis barrier – A physical barrier between the blood vessels and the seminiferous tubules of the animal testes
- Blood–thymus barrier – A barrier formed by the continuous blood capillaries in the thymic cortex
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Blood–ocular barrier.