Types of Diabetic Retinopathy

posted in: Eye Conditions

Diabetes is a condition when the pancreas does not produce a sufficient amount of insulin to properly regulate the body’s blood sugar level.  Over time diabetes can affect multiple organ systems including the kidneys, heart, and nervous system, the circulation, and the eyes.  When it does, the very fine blood vessels in the body, including those in and around the eye, are damaged.

Damage to blood vessels in the retina from diabetes is known as diabetic retinopathy.  The prevalence of diabetic retinopathy is associated with duration of diabetes, and nearly all persons with type 1 diabetes and over 60% of those with type 2 diabetes have some form of diabetic retinopathy after 20 years.  Diabetic retinopathy is most commonly seen in adults (adult-onset diabetes) but it is also encountered in children (juvenile-onset diabetes).

Diabetic retinopathy can be separated into two main categories: background retinopathy and proliferative retinopathy.

Background diabetic retinopathy may occur after having diabetes for several years and may be totally asymptomatic (you may not be aware of diabetic affectintg your eyes).  On examination, the retina is found to have red dots that consist of small hemorrhages and microaneurysms (dilated capillaries).  In early background diabetic retinopathy most patients may not expereince any functional visual loss, but as time goes on the microaneurysms may leak fluid or lipids into the delicate central part of the retina (known as the macula) and cause macular edema (swelling of the retina).  Macular edema causes blurred or distorted vision.  Treatment of macular edema associated with background diabetic retinopathy consists of laser treatment to the dilated capillaries.  Laser treatment helps prevent leakage from dilated capillaries and also promotes reabsorption of the macular edema.

Proliferative diabetic retinopathy is less commonly encountered.  However, this form of diabetic retinopathy is a more serious condition.  In proliferative diabetic retinopathy, abnormal blood vessels develop over the retina and optic nerve.  These new blood vessels tend to break and easily bleed since they are very fragile.  Bleeding into the retina or on the central jelly in the eye (vireous jelly) can cause a sudden loss of vision.  Bleeding in the retina or vitreous or retina may take months to reabsorb.  Blood inside the eye can form scar tissue that can pull on the retina and cause it to detach (retinal detachment).  Argon laser treatment primarily of the peripheral retina often causes these new, fragile blood vessels to regress and help prevent them from bleeding.  Removal of a hemorrhage inside the eye may be needed depending on the size and duration of the hemorrhage.  This procedure is known as a virectomy and can be combined with a retinal detachment repair depending on the status of the retina.  Additional laser treatment can also be performed at the time of virectomy.

Therapy for diabetes is directed to maintain a blood glucose level within an acceptable range.  An acceptable level of blood sugar helps to minimize damage to the eyes and other organ systems.  Treatment involves proper nutrition, diet, and exercise.  Medications such as insulin or oral agents help lower blood sugar to prevent complications from diabetes.

Early detection is important for successful treatment of diabetic retinopathy.  Ophthalmologic findings may help guide treatment of diabetes.  Early treatment of diabetic retinopathy may help prevent the disease from progressing into advanced stages.  Studies have shown that early treatment of diabetic retinopathy decreases the risk of developing profound vision loss.  Many ophthalmologists recommend a yearly eye examination for all diabetic patients to detect and monitor diabetic retinopathy.

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