The Blood-Retinal Barrier in the Management of Retinal Disease: EURETINA Award Lecture

Retinal diseases are the main causes of blindness in the Western world. Diabetic retinopathy and age-related macular degeneration continue to increase in prevalence and as main causes of vision loss. Intravitreal anti-VEGF and steroid injections have raised new expectations for their successful treatment. These agents act by stabilizing the blood-retinal barrier (BRB). Our group defined the BRB by identifying for the first time the tight junctions that unite retinal endothelial cells and are the basis for the inner BRB, an observation later confirmed in retinal pigment epithelial cells and in brain vessels. A major role of active transport processes was also identified. Today, the BRB is understood to play a fundamental role in retinal function in both health and disease. Retinal edema, an ubiquitous manifestation of retinal disease, is directly associated with breakdown of the BRB and with vision loss. In its most common form (i.e., vasogenic edema), due to breakdown of the BRB, Starling’s law of capillary filtration may be used to interpret the mechanisms of fluid accumulation in the retina. The main factors involved in the development of retinal edema are BRB permeability, capillary hydrostatic pressure, tissue hydrostatic pressure, Received: December 29, 2016 Accepted: January 2, 2017 Published online: February 3, 2017 Ophthalmologica José Cunha-Vaz, MD, PhD AIBILI Azinhaga de Santa Comba, Celas PT–3000-548 Coimbra (Portugal) E-Mail cunhavaz @ aibili.pt © 2017 S. Karger AG, Basel