These biochemical changes include protein glycation
as seen in hemoglobin A1C (Brownlee et al., 1984); Protein Kinase-
C activation which may lead to enhanced permeability of retinal
vasculature, basement membrane thickening and cellular
signaling by vascular endothelial growth factors (VEGF) (Xia
et al., 1996; Miller et al., 1997)