SYP and diabetes mellitus: Previous studies demonstrated that one month of diabetes decreases the retinal expression of BDNF and synaptophysin [1, 3], and that the antioxidant lutein prevented BDNF and synaptophysin reduction and avoided increase in cleaved caspase-3 in the diabetic retina [3] suggesting that local oxidative stress has a neurodegenerative influence in diabetic retina.