Joussen, Antonia M., Gardner, Thomas W., Kirchhof, Bernd, Ryan, Stephen J., Phillips, Brett E., Antonetti, David A., and Berkowitz, Bruce A.
Proper retinal function requires the presence of a well-defined blood-retinal barrier (BRB). In many of the leading causes of medical blindness this BRB is compromised. Indeed, retinopathy of prematurity and age related macular degeneration both include production of aberrant vessels with poor barrier properties. Further, diabetic retinopathy, the leading cause of blindness in working age adults, involves progressive vision loss and is closely associated with macular edema [117]. Increased fluid accumulation, as well as lipid and albumin deposits, is believed to be the result of the breakdown of the BRB that normally controls the neuronal environment. Barrier dysfunction results in increased permeability which diagnostically indicates progressive retinopathy [32]. This chapter will review the normal physiology of the BRB, the changes that occur through the course of diabetic retinopathy, and the known underlying molecular mechanisms that may lead to barrier dysfunction. Elucidating the mechanisms of barrier dysfunction in diabetic retinopathy will further our understanding of its pathogenesis and provide future therapeutic targets. [ABSTRACT FROM AUTHOR]