Foresight: Advances in Diagnosis and Management of Diabetic Retinopathy

Jointly sponsored by the Center for Accredited Healthcare Education and International Medical Press

Supported by an educational grant from Eli Lilly and Company

Diabetic retinopathy is the 5th leading cause of blindness globally. Although the link between hyperglycemia and diabetic retinopathy is poorly understood, a number of theories have been put forth to describe this relationship, including loss of capillary supporting cells, basement membrane thickening, increased adhesion among endothelial cells, and increased leukostasis.

The major stages of diabetic retinopathy include no apparent retinopathy, 3 levels of nonproliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy. Diabetic macular edema (DME) can be present when any degree of diabetic retinopathy is present. DME is classified as either absent or present. When DME is present, it is subcategorized as mild, moderate, or severe, with more severe DME occurring closer to the center of the macula.

There are a variety of screening techniques available to detect diabetic retinopathy and DME. Available options include direct ophthalmoscopy, indirect ophthalmoscopy, slit-lamp biomicroscopy, fundus photography, fluorescein angiography, ultrasonography, and optical coherence tomography (OCT). Ideally, patient should be screened with indirect ophthalmoscopy, but this techniqure requires pupil dilation that may present a problem with patient adherence. Because diabetic retinopathy is best treated when detected early, screening is an essential component of the care of patients with diabetes.

Current pharmacologic options for the treatment of diabetic retinopathy are limited to strategies to control risk factors such as hyperglycemia, dyslipidemia, and elevated blood pressure. Once diabetic retinopathy is diagnosed, laser photocoagulation and vitrectomy are the most frequently employed options. A number of new pharmacologic options are also being explored. Numerous intravitreal therapies are currently in development for the treatment of diabetic retinopathy. These therapies include corticosteroid, enzyme, and anti-VEGF treatments. In terms of emerging systemic therapies currently being explored, a number of agents approved for other uses are being examined as treatment options for diabetic retinopathy. Approved drugs seeking a retinopathy indication include drugs from a variety of classes (eg, statin, angiotensin receptor blocker, COX-2 inhibitor, somatostatin analog, and angiotensin converting enzyme [ACE] inhibitor). Novel systemic therapies, such as the protein kinase C inhibitors midostaurin and ruboxistaurin have been shown to improve visual acuity and reduce the risk of moderate visual loss, respectively; however, ruboxistaurin has a more favorable side effect profile.

In summary, diabetic retinopathy is a significant cause of morbidity. Timely screening and treatment are of critical importance. Current standard of care for diabetic retinopathy includes management of glucose, lipids, and blood pressure, as well as surgery when needed. A number of emerging therapies will likely become available in the near future. Such options include intravitreal injections, systemic therapies that have other indications, and novel systemic therapies.