The application discloses compositions and methods for preventing and treating diabetic retinopathy. It is disclosed herein that an inhibitor of microRNA-let-7b administered to the eye of a subject in need thereof is useful for preventing and treating several problems associated with diabetic retinopathy and plays a role in vasculature stabilization, increasing retinal thickness, reducing retinal capillary dropout, diminishing microvascular leakage, preventing or treating hyperproliferation of microvascular cells, and stabilizing aberrant neovascularization. The invention includes the use of various kinds of inhibitors of microRNA-let-7b, including, but not limited to, an antagomir of miRNA-let-7b. A useful compound of the invention can be administered into the eye, including intravitreally. A useful antagomir is Dy547-mA(*)mA(*)mCmCmAmCmAmCmAmAmCmCmUmAmCmUmAmCmCmU(*) mC(*)mA (*)(3′-Chl).
