Administration of TZDsmay, in patients with AMD, slow the progression to CNV, and in patients withdiabetic retinopathy attenuate the progress to PDR, provided that: (1) theirrisk of macular edema is low, (2) they lack symptoms of CHF or cardiomyopathy,and (3) are not taking insulin or nitrates. This evidence concerns the gene INS and macular retinal edema.