Protective factors in diabetic retinopathy: focus on blood-retinal barrier.

The earliest and most significant change in diabetic retinopathy (DR) is blood-retinal barrier (BRB) dysfunction, followed by two main pathologies that may cause severe visual impairment: Diabetic Macular Edema (DME) and Proliferative Diabetic Retinopathy (PDR). The pathological hallmarks of BRB dysfunction include loss of tight junction integrity, VEGF- and AGE-induced damage, oxidative stress, and inflammatory changes. Recently, several BRB protective factors have been reported. Our aim is to give a review of those protective factors and discuss new potential therapeutic targets for DR.