Future Pharmacotherapies for Diabetic Retinopathy

Currently, there are no pharmacotherapies that directly target diabetic retinopathy. Rather, they are aimed at controlling known risk factors, such as poor glycemic control, hypertension, and dyslipidemia. The aims of pharmacotherapy are to treat vessel leakage and reduce the progression of diabetic retinopathy. Intravitreal triamcinolone has been shown to improve vision and reduce diabetic macular edema, but the effects are temporary, and treatment may result in complications. A number of anti-VEGF therapies are also available. Treatment with pegaptanib has been shown to facilitate the regression of neovascularization, improve visual acuity, and reduce retinal thickness. Somatostatin exerts a number of beneficial effects, including inhibition of growth hormone, suppression of insulin-like growth factor-1 (IGF-1), and decreasing endothelial cell proliferation. The somatostatin analog octreocide has been shown to reduce the progression of diabetic retinopathy and reduce the need for laster therapy. Protein kinase β (PKC- β) has been shownt to increase vascular permeability, extracellular matrix production, and cell proliferation. Inhibition of PKC- β inhibits both VEGF-induced endothelial cell proliferation and increased vascular permeability. Treatment with the PKC- β inhibitor ruboxistaurin has been shown to preserve visual loss and may be particularly beneficial among patients with more severe edema. A successful therapy should demonstrate efficacy, specificity, selectivity, a favorable side effect profile, a desirable form of application, and cost effectiveness. These new treatments are aimed at improving visual outcomes while addressing these other important issues.