Diabetic Retinopathy

Diabetic retinopathy is retinal damage caused by chronic diabetes-related microvascular injury. Persistently elevated glucose injures retinal capillary walls, making them weak, leaky, and prone to closure. The retina depends on this fine capillary network for oxygen; when vessels leak, fluid and blood enter retinal tissue, and when vessels close, areas of retina become ischemic. Early damage produces non-proliferative diabetic retinopathy (NPDR). Findings include microaneurysms, small capillary outpouchings that are often the first visible change; retinal hemorrhages; and fluid leakage. NPDR may be mild, moderate, or severe. A person can have clinically significant retinal disease while reporting no visual symptoms. Leakage near the macula can cause diabetic macular edema (DME). The macula provides central, detailed vision, so swelling in this area may cause blurred reading vision, trouble recognizing faces, or distorted straight lines. Centre-involved DME threatens visual function because the swelling involves the central macula. When ischemic retina releases signals that stimulate new vessel growth, the condition becomes proliferative diabetic retinopathy (PDR). These new vessels are fragile and abnormal. They can bleed into the vitreous, causing a sudden haze, dark floaters,...