Asheesh Tewari, MD the Retina Expert :: Patient Education
Patient Education :: Diabetes and Diabetic Retinopathy

Diabetes mellitus is a condition which impairs the body's ability to use and store sugar. Diabetes can cause serious changes in the blood vessels throughout the body, including the eye and kidney. It can cause complications with ulcers in the feet. Diabetic retinopathy can start without symptoms and can get worse over time. If you are a diabetic, you can protect and preserve your eyesight by keeping your blood sugar under control, learning about your eyes, having eye exams regularly and following your doctor's treatment plan.

What is diabetic retinopathy?

Diabetes can weaken your body's blood vessels. If you have diabetic retinopathy, the blood vessels in the eye go through a series of changes.

These changes include:
1. Leaking blood vessels.
2. Closed blood vessels.
3. Weak new blood vessels.

If you have leaking blood vessels, fluid from the retina leaks and bulges from the tiny blood vessels. It can cause swelling near the fovea, which is the center part of the vision. This swelling is called macular edema. If there are closed blood vessels, this can again cause loss of vision from poor circulation. If you have weak new blood vessels, these vessels may grow and the jelly in the eye can pull on the retina, causing bleeding within the cavity of the eye.

There are two forms of diabetic retinopathy. One form is called nonproliferative diabetic retinopathy. With this form the blood vessels leak and cause swelling of the retina. This is considered to be an early stage of diabetic retinopathy. This type of retinopathy is a warning sign that can sometimes progress to a more serious sight threatening condition called proliferative retinopathy. If you develop proliferative retinopathy, the weak and new blood vessels can bleed into the vitreous jelly, causing clouding of vision. Additionally, if scar tissue forms from the ruptured blood vessels, this can pull and tug on the retina and cause a retinal detachment. Sometimes blood vessels grow onto the front part of the eye and cause a particular type of glaucoma.

What are the symptoms of diabetic retinopathy?

Blurred vision can be a symptom of diabetic retinopathy, but sometimes patients who are diabetic have no symptoms of diabetic retinopathy. When bleeding occurs in proliferative retinopathy, patients describe symptoms of many floaters or spider webs in their field of vision, with hazy vision.

How is one diagnosed with diabetic retinopathy?

A complete ophthalmologic examination performed by a retina specialist is necessary to diagnose diabetic retinopathy. In addition to the ophthalmic examination, photographs of the back of the eye, along with a dye test called a fluorescein angiogram are sometimes needed to look at the circulation in the back of the eye. These techniques help to classify your condition and the changes in the retinal blood vessels and guide laser treatment. The fluorescein dye travels to the retina to highlight the abnormal blood vessels in the back of the eye. The dye will leave your body a few hours after the test. It is not uncommon for the skin, eye and urine to turn bright yellow after the test.

What is the treatment for diabetic retinopathy?

Treatment can include laser surgery done in the office or a vitrectomy procedure performed in the operating room. Typically, the laser beam is used and focused on diseased areas of the retina. The energy seals or destroys the diseased areas. The laser scars reduce abnormal blood vessel growth and help bond the retina to the back of the eye. This treatment does not require an incision and is usually performed in the office. The laser treatment is usually done in two to three sessions over a period of time. Different methods of treatment are used for leaky blood vessels and for new blood vessels. If leaky blood vessels are found, the laser is only applied specifically to the diseased areas to seal the tiny areas of leakage. If new blood vessels are profound, the laser is applied to all areas of the retina to reduce new blood vessel growth. Despite laser treatment, some patients may end up needing vitrectomy or surgery to remove the vitreous jelly, which is covered with blood. The timing of this depends on the extent of the damage to the eye, as well as the condition of the other eye. Vitrectomy is used for bleeding into the vitreous or for the vitreous pulling on the retina, causing retinal detachment. This is usually done after other treatments have been tried. During this procedure, additional laser photocoagulation is usually done once the blood has been cleared and/or scar tissue that has formed on top of the retina from the new blood vessels has been removed.

What can I expect after laser treatment?

After laser treatment a patch may be placed over the eye. You may have temporary side effects such as watery eyes, dilated pupils or a mild headache. Sometimes you will have double vision or blurry vision, and a loss of peripheral or night vision. These side effects usually get better with time. Early detection of diabetic retinopathy is the best protection against loss of vision. Even when patients are asymptomatic, an eye exam should by performed once a year by your eye doctor. Exams should be scheduled more frequently if the diabetic retinopathy has shown signs of worsening.