Diabetic retinopathy Home A-Z Health Information Health Library A-Z Diabetic Retinopathy Overview Diabetic retinopathy, a common complication associated with diabetes, refers to high blood sugar-induced damage to the retina, which comprises layers of light-detecting cells. If left untreated, diabetic retinopathy can cause blindness. However, the progression of diabetic retinopathy to the visual impairment stage takes a long time. Causes Over time, excess sugar in the blood causes the blockage of the tiny blood vessels nourishing the retina. This results in the blood supply to the retina to be cut off. Angiogenesis (the growth of new blood vessels) often serves a natural strategy to counter loss of blood vessels. However, the improper development of these new blood vessels causes them to spring leaks. Diabetic retinopathy can be categorised into two main types each with distinct causes:Early diabetic retinopathy: This is a common form. In this condition, new blood vessels are not growing (proliferating). Thus, this condition is also called non-proliferative diabetic retinopathy (NPDR). In NPDR, the walls of the blood vessels in your retina weaken, causing the protrusion of tiny bulges from the walls of the smaller vessels. Sometimes, these bulges may cause the leakage of blood and fluid into the retina. Although this condition is unlikely to affect vision, it can progress to a state at which it is sight threatening. Mild NPDR and moderate-to-severe NPDR (the condition worsens, owing to increased bleeding into the retina) increase the risk of vision loss in the future.Advanced diabetic retinopathy: In some cases, diabetic retinopathy progresses to this severe type (also called proliferative diabetic retinopathy; PDR). PDR is accompanied by diabetic macular oedema. In PDR, blood vessels in the retina are blocked, resulting in a loss of blood supply. This promotes abnormal angiogenesis in the retina. Scar tissue formation resulting from the growth of these fragile blood vessels and the leakage of blood from these vessels into the vitreous humour (the clear, jellylike substance in the central part of the eye) lead to retinal detachment, increased intraocular pressure, optic nerve damage, and vision loss. Although the peripheral vision is not affected, without treatment, patients may be unable to perform daily activities, such as reading or driving. Symptoms Regular diabetic retinopathy screening is important because symptoms are not always noticeable until the condition has progressed to a serious stage. The early signs of diabetic retinopathy can be detected during these routine eye tests. This will aid the administration of the correct treatment to ensure that vision loss does not occur.Diabetic retinopathy can also cause other symptoms:Gradual deterioration of vision, including blurry or patchy vision.Sudden vision loss.Redness or pain in the eye.Eye floaters. Diagnosis Comprehensive dilated eye examinations are often the best method to diagnose diabetic retinopathy. In this examination, the pupils are widened (dilated) via the administration of specialised drops so that the ophthalmologist has a clear view of the regions within the eyes. These drops often cause the blurring of vision, but their effects wear off in a few hours. The ophthalmologist will examine different parts of the eyes for abnormalities using the following techniques:Fluorescein angiography: After the eyes are dilated, the dye fluorescein is injected into a vein (in the arm). Images are captured as the dye circulates through the ocular blood vessels. These images help identify broken, leaky, or closed blood vessels.Optical coherence tomography (OCT): Cross-sectional images of the retina are obtained. These images help the doctors ascertain the retinal thickness, enabling the determination of the extent of fluid leakage into the retinal tissues. Treatment Diabetic retinopathy treatment is required only if notable problems are detected during screening. Preventive measures to lower the risk include:Diabetes treatment (controlling blood sugar, pressure, and cholesterol and regular intake of diabetes medication).Maintaining a healthy lifestyle.Regular eye examinations.However, for advanced-stage diabetic retinopathy, specific treatments may be required. These include:Laser photocoagulation for patients with diabetic macular oedema. Small laser burns are introduced in the damaged areas of the retina to reduce fluid leakage. While this treatment may not result in notable vision improvement, it does help suppress further deterioration of vision.Injection of anti-VEGF drugs into the eye.Surgical procedures for scar tissue removal and elimination of blood leaking into the eye may be needed for patients with severe diabetic retinopathy.