Diabetic retinopathy is a type of diabetic eye disease and is the most common cause of vision loss among people with diabetes. It is also a leading cause of blindness among working-age adults. It involves changes to retinal blood vessels that can cause them to bleed or leak fluid, distorting vision. Diabetic macular edema is a consequence of diabetic retinopathy, which causes swelling in the centre of the retina.
Chronically high blood sugar from diabetes is associated with damage to the tiny blood vessels in the retina, leading to diabetic retinopathy. The retina detects light and converts it to signals sent through the optic nerve to the brain. In diabetic retinopathy, blood vessels in the retina leaks fluid or bleeds, distorting vision. In its most advanced stage, new abnormal blood vessels grow on the surface of the retina, which can lead to scarring and cell loss in the retina.
People with all types of diabetes (type 1, type 2, and gestational) are at risk for diabetic retinopathy. Risk increases the longer a person has diabetes. Women who develop or have diabetes during pregnancy may have rapid onset or worsening of diabetic retinopathy.
The early stages of diabetic retinopathy usually have no symptoms. The disease often progresses unnoticed until it affects vision. Bleeding from abnormal retinal blood vessels can cause the appearance of “floating” spots. These spots sometimes clear on their own. But without prompt treatment, bleeding often recurs, increasing the risk of permanent vision loss.As diabetic retinopathy often goes unnoticed until vision loss occurs, people with diabetes should get a comprehensive dilated eye examination at least once a year. Early detection, timely treatment, and appropriate follow-up care of diabetic eye disease can protect against vision loss.
Vision lost due to diabetic retinopathy is sometimes irreversible. However, early detection and treatment can reduce the risk of blindness by 95%. As diabetic retinopathy often lacks early symptoms, people with diabetes should get a comprehensive dilated eye examination at least once a year. People with diabetic retinopathy may need eye examinations more frequently.Women with diabetes who become pregnant should have a comprehensive dilated eye examination as soon as possible. Additional examinations during pregnancy may be needed.For diabetic patients, some other ways to prevent or delay vision loss due to diabetic retinopathy include taking medication as prescribed, staying physically active, and maintaining a healthy diet.
Diabetic retinopathy is detected during a comprehensive dilated eye examination that includes:
Treatment for diabetic retinopathy is often delayed until it starts to progress to Proliferative Diabetic Retinopathy (PDR), or when diabetic macular edema occurs. People with severe non-proliferative diabetic retinopathy have a high risk of developing PDR and may need a comprehensive dilated eye examination as often as every twp to four months.Diabetic retinopathy can be treated with several therapies, used alone or in combination.
For decades, PDR has been treated with scatter laser therapy known as panretinal photocoagulation. Treatment involves making 2000 to 3000 tiny laser burns in areas of the retina away from the macula. These laser burns are intended to cause abnormal blood vessels to shrink. Although treatment can be completed in one session, two or more sessions are sometimes required. While it can preserve central vision, scatter laser surgery may cause some loss of side (peripheral), colour, and night vision. Scatter laser surgery works best before new, fragile blood vessels have started to bleed.
Anti-VEGF drugs are injected into the vitreous gel to block a protein called vascular endothelial growth factor (VEGF), which can stimulate abnormal blood vessels to grow and leak fluid. Available anti-VEGF drugs include Avastin (bevacizumab), Lucentis (ranibizumab), and Eylea (aflibercept).Recent studies have shown that anti-Vascular Endothelial Growth Factor (VEGF) treatment not only is effective for treating diabetic macular edema, but is also effective for slowing progression of diabetic retinopathy, including PDR, so anti-VEGF is increasingly used as a first-line treatment for PDR.