Muh-Shy Chen a, Ping-Kang Hou a, Tong-Yuan Tai b, Boniface Juisiang Lin c
aDepartment of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
bDepartment of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
cDepartment of Internal Medicine, Cardinal Tien Hospital and School of Medicine, Fu Jen Catholic University, Taipei, Taiwan
Abstract
There are two main blood-ocular barriers, the blood-aqueous barrier and the blood-retinal barrier. The blood-aqueous barrier is formed by the nonpigmented ciliary epithelium of the ciliary body and the vascular endothelium of the iris vessels. The blood-retinal barrier is formed by the vascular endothelium of the retinal vessels and the retinal pigment epithelium. Four methods of examination are currently used to study the function of blood-ocular barriers. Among these, laser flare-cell photometry is a noninvasive, quantitative method to evaluate the permeability of the blood-aqueous barrier. Vitreous fluorophotometry is an excellent technique to quantitate blood-retinal barrier function. Fluorescein angiography and optical coherence tomography are excellent qualitative imaging techniques to evaluate blood-retinal barrier function. Current basic research shows prostaglandin E2 and other mediators may produce breakdown of the blood-aqueous barrier, and vascular endothelial growth factor plays an important role in the breakdown of the blood-retinal barrier. Retinal laser photocoagulation can induce breakdown of both the blood-aqueous and blood-retinal barriers in pigmented rabbits. The four methods of examination described herein are excellent measures for clinical application to evaluate blood-ocular barrier function in various ocular diseases, many of which are discussed here. [Tzu Chi Med J 2008;20(1):25–34]
Keywords
Blood-aqueous barrier; Blood-ocular barrier; Blood-retinal barrier
