<p>This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</p> <p>Many growth factors are implicated in the pathogenesis
of proliferative diabetic retinopathy. Alteration of growth
factors and their receptors in diabetes has been shown in
both experimental and clinical studies. Sustained hyperglycemia
resulting from long-standing diabetes leads to several
biochemical abnormalities that consequently result in
retinal hypoxia. Retinal oxygenation state regulates various
growth factors that promote angiogenesis in order to meet
the oxygen demands of the tissue. However, unregulated expression
of these growth factors and induction of complex
cascades leading to augmentation of other proangiogenic
factors, which may not be regulated by tissue oxygenation,
leads to uncontrolled retinal neovascularization and blindness
in diabetic patients.</p>
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Exp Diabesity Res. 2003; 4(4):287-301