Foreword: Evaluation of New Treatment Paradigms for Diabetic Retinopathy and Macular Edema

Abstract

This is an interesting time in diabetic retinopathy research. Multiple clinical trials have demonstrated that currently available medications and treatments can slow the development of diabetic complications and reduce the risk of blindness. I have been fortunate to be involved in a 6-year collaboration between Eli Lilly & Co. and the National Eye Institute, which has focused on promising medical treatments for diabetic retinopathy and diabetic macular edema. As we discuss promising medical treatments for diabetic retinopathy, we need to consider them as being complementary to, and not replacements for, the best practices now being applied. The United Kingdom Prospective Diabetes Study (UKPDS) 2 and the Diabetes Control and Complications Trial (DCCT) 1 showed that we can slow the progression of DR by controlling blood sugar, serum lipids, and blood pressure in both type 1 and type 2 diabetes. In the DCCT, intensive medical control slowed the progression of retinopathy by more than 50%. We still work to improve on that, because achievement of the targets of intensive medical control, even today, remains a near-impossible task. (I have enormous respect for my patients who are able to control blood glucose and maintain their HbA1c 7.) The Early Treatment Diabetic Retinopathy Study (ETDRS) and Diabetic Retinopathy Study (DRS) showed that scatter photocoagulation can substantially reduce the risk of severe blindness from proliferative diabetic retinopathy. However, treatment for diabetic macular edema has not been as successful, and I believe that this is a greater problem for us. We have shown that focal photocoagulation and grid photocoagulation, where needed, may reduce the risk of vision loss from diabetic macular edema by 50%. Involvement of the center with diabetic macular edema is the key, and the question is whether new agents, such as anti-angiogenics, vascular endothelial growth factor inhibitors, and protein kinase C inhibitors, will be effective. Aldose reductase inhibitors are still under investigation. Additionally, interest remains in advanced glycated endproduct inhibitors and growth hormone antagonists. Treatments to manage blood pressure and decrease lipids have improved the management of diabetic complications, and promising treatments that directly target the microvascular complications of diabetes are on the horizon. This supplement, arising from a CME-accredited satellite symposium held in New Orleans on the occasion of the 2001 meeting of the American Academy of Ophthalmology, is just an opening salvo to help us look toward the future. Of course, to prevent blindness, regular screening, careful follow-up, and timely treatment are essential building blocks in effective medicine. To those building blocks, it is hoped that we can soon add innovative treatments.