ABSTRACT
Epithelial and/or endothelial cells sealed by tight junctions serve as the major membrane barriers for the transport of nutrients, ions, and drugs into intraocular tissues. The principal membrane barriers of the eye are located in the cornea, conjunctiva, iris-ciliary body, lens epithelium, and retina (Fig. 1). Various specialized transport processes in these barriers control the movement of solutes into and out of intraocular chambers. These processes maintain the visual function, control intraocular pressure, provide nutrients to avascular cornea and lens, and protect ocular tissues from xenobiotics. An alteration in the function of these transporters is often the underlying cause of various ocular diseases. In addition, these transport processes can play a role in drug transport.
