A Clinico-Pathological Study of the Structural and Functional Changes to the Retina Following Anti-VEGF Treatments for Diabetic Macular Edema

Diabetic retinopathy (DR) causes changes in the capillaries that nourish the retina. Two treatments clinically used for DR are laser photocoagulation to reduce the angiogenic drive by knocking off metabolically active retina and anti-VEGF drugs for diabetic macular edema (DME). DME affects approximately 2.5% of the nearly 2.4 million Canadians with diabetes, or approximately 60,000 Canadians, making it a major cause of adult-onset vision loss. DME occurs when blood vessels in the retina of diabetic patients become leaky resulting in unwanted fluid accumulation in the center of vision known as the macula. If not treated, this can lead to blindness. Originally used in the treatment of age-related macular degeneration (AMD), anti-VEGF drugs are increasingly used to control leakage and abnormal growth of retinal blood vessels. Numerous questions have emerged following the usage of anti-VEGF medications in the eye such as their long-term effects of these drugs on intraocular pressure and on the overall retinal perfusion. By recruiting DR patients requiring anti-VEGF treatment for DME, this study will answer whether long-term usage of anti-VEGF will result in structural and functional changes to the retina.