VIP and diabetic retinopathy: Interestingly, NAP, similar to VIP, seems to play different protective effects against pathologic changes induced by diabetic retinopathy, as it reduced both inflammation [194] and apoptosis [195] as well as the levels of HIF1-α and of VEGF [196] in retinas of rats with STZ-induced diabetes, and protected the integrity of the outer BRB exposed to hyperglycemic/hypoxic or inflammatory insult [194,197].