What is Diabetic Retinopathy?
Diabetic Retinopathy (DR) is one of several complications that can occur as a result of diabetes. Diabetes can cause progressive damage to the retina, the light-sensitive lining at the back of the eye. DR is the most serious sight-threatening complication of diabetes. The longer a person has diabetes, the higher the risk of developing retinal damage. DR is due to an elevation in blood sugar which causes damage to the delicate blood vessels inside the eye, causing them to leak, bleed and become blocked. Sometimes the body grows fragile new blood vessels (neovascularization) within the retina. If untreated, DR can lead to permanent vision loss and blindness.
Types of Diabetic Retinopathy:
Non-proliferative Diabetic Retinopathy (NPDR)
With NPDR, tiny blood vessels leak, making the retina swell. When the macula swells, it is called macular edema. This is the most common reason why people with diabetes lose their vision. About half all people with DR will develop macular edema (ME). Although it is more likely to occur as DR worsens, ME can happen at any stage of the disease. The macula is the part of the retina that provides central vision, it allows color perception and fine detail. If the macula swells, it causes blurred vision. Also, with NPDR, blood vessels in the retina can close off. This is called macular ischemia. When that happens, blood cannot reach the macula. Sometimes tiny particles called exudates can form in the retina. These can affect vision too.
Proliferative Diabetic Retinopathy (PDR)
PDR is a more advanced stage of DR. It happens when the retina starts growing new blood vessels. This is called neovascularization. These blood vessels attempt to improve blood circulation in the compromised retina, however these vessels are fragile and often break and bleed into the vitreous. If they only bleed a little, it may result in a few dark floaters. If they bleed a lot, it might block all vision. These new vessels can form scar tissue. Scar tissue can cause problems with the macula or lead to a detached retina. PDR is very serious and can affect both the central and peripheral (side) vision.
Symptoms:
Blurred vision or Fluctuating vision
Changes in central vision
Blank or dark areas in the field of vision
Difficulty with night vision
Floating spots
Sudden vision loss
Risk Factors:
Diabetes – people with Type 1 or Type 2 diabetes are at risk. The longer a person has diabetes, the higher the risk, especially if the diabetes is poorly controlled.
Race – Hispanics and African Americans are at a greater risk for developing DR.
Hypertension – people with other medical conditions, such as high blood pressure and high cholesterol, are at greater risk.
Pregnancy – pregnant women have a higher risk of developing diabetes and DR. If a woman has gestational diabetes, she has a higher risk of developing diabetes as she ages.
Smoking and alcohol use
Detection of DR:
A comprehensive dilated eye exam allows the doctor to check the retina for:
Changes to blood vessels
Leaking blood vessels
Swelling of the macula (ME)
Changes in the lens
Damage to nerve tissue
If macular edema or new blood vessel growth are suspected, an OCT or fluorescein angiogram (FA) may be performed. An OCT uses light waves to provide detailed images of the retinal layers, whereas FA uses a fluorescent dye injected into an arm vein, to obtain photographs of the retinal blood vessels as the dye reaches the eye. This will detect damaged or leaky blood vessels.
Treatment:
Treatment for DR depends on the stage of the disease. The goal is always to slow or stop the progression of the disease.
In its early stages, DR can be treated with laser therapy (photocoagulation) to seal leaking blood vessels or to discourage other blood vessels from leaking. Injections are also used in some cases to inhibit the growth of new blood vessels. In more advanced cases, surgery may be required. People may need a procedure to remove and replace the gel-like fluid in the back of the eye, the vitreous. Surgery may also be needed to repair a retinal detachment. Diabetes and its complications can affect many parts of the eye. It can also contribute to the onset of cataracts, glaucoma, double vision and decreased corneal sensitivity. Some damage is irreversible. For this reason, it is critical to have annual dilated eye exams to monitor the progress of the eye disease. People with diabetic retinopathy may need exams more frequently, those at a high risk of developing PDR may need a dilated eye exam as often as every 2-4 months.
The best form of treatment is prevention. Monitoring and maintaining tight control of blood sugar is crucial. Regular visits to a primary care physician are necessary, as well as adhering to specific dietary instructions, exercise and medication. It’s also important to see an eye doctor annually. A person with DR might only notice symptoms after significant damage is done. An eye doctor will be able to detect retinal changes much sooner and can help prevent vision loss.
If you notice vision changes in one or both eyes, call your eye doctor right away!
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