Diabetic Retinopathy

Diabetic retinopathy (DR), also known as diabetic edema or geographic atrophy, is a condition occurring in persons already diagnosed with diabetes, which causes progressive damage to the retina, resulting in vision loss or blindness. Typically, DR is the result of damage to the tiny blood vessels that nourish the retina. They leak blood and other fluids that cause swelling of retinal tissue and clouding of vision. The condition usually affects both eyes and the longer a person has diabetes, the more likely they will develop diabetic retinopathy and if left untreated, will result in blindness.

What should I know about DR?

There are two types of DR:

Non-proliferative diabetic retinopathy (NPDR) is the early state of the disease in which symptoms will be mild or non-existent. In NPDR, the blood vessels in the retina are weakened causing tiny bulges called microanuerysms to protrude from their walls.

Proliferative diabetic retinopathy (PDR) is the more advanced form of the disease. At this stage, new fragile blood vessels can begin to grow in the retina and into the vitreous, the gel-like fluid that fills the back of the eye. The new blood vessel may leak blood into the vitreous, clouding vision. Other complications of PDR include detachment of the retina due to scar tissue formation and the development of glaucoma. Glaucoma is an eye disease defined as progressive damage to the optic nerve. In cases of proliferative diabetic retinopathy, the cause of this nerve damage is due to extremely high pressure in the eye. If left untreated, proliferative diabetic retinopathy can cause severe vision loss and even blindness.

What are the symptoms of DR?

Symptoms of diabetic retinopathy include:

- Seeing spots or floaters in your field of vision

- Blurred vision

- Having a dark or empty spot in the center of your vision

- Difficulty seeing well at night

There are often no visual symptoms in the early stages of diabetic retinopathy. The American Optometric Association recommends that everyone with diabetes have a comprehensive dilated eye examination once a year.

What causes Diabetic Retinopathy?

Risk factors for diabetic retinopathy are:

Diabetes - People with Type 1 or Type 2 diabetes are at risk for the development of diabetic retinopathy. The longer a person has diabetes, the more likely they are to develop diabetic retinopathy.

Race - Hispanics and African Americans are at greater risk for developing diabetic retinopathy.

Medical conditions - Persons with medical conditions such as high blood pressure and high cholesterol are at greater risk.

Pregnancy - Pregnant women face a higher risk for developing diabetes and diabetic retinopathy. If gestational diabetes develops, the patient is at much higher risk of developing diabetes as they age.

How is diabetic retinopathy diagnosed?

Diabetic retinopathy can be diagnosed using a comprehensive eye examination with special emphasis on evaluation of the retina and macula. This will include:

- Patient history to determine vision difficulties experienced by the patient, presence of diabetes, and other general health concerns that may be affecting vision

- Visual acuity measurements to determine the extent to which central vision has been affected

- Refraction to determine the need for changes in an eyeglass prescription

- Evaluation of the ocular structures, including the evaluation of the retina through a dilated pupil

- Measurement of the pressure within the eye

Supplemental testing may include:

- Retinal photography or tomography to document current status of the retina

- Fluorescein angiography to evaluate abnormal blood vessel growth

How is diabetic retinopathy treated?

Treatment for diabetic retinopathy depends on the stage of the disease and is directed at trying to slow or stop the progression of the disease. In the early stages of Non-proliferative Diabetic Retinopathy, treatment other than regular monitoring may not be required. Following your doctor's advice for diet and exercise and keeping blood sugar levels well-controlled can help control the progression of the disease. For Proliferative DR, there are several treatments available and several more in development.

Laser treatment/photocoagulation - A laser beam of light is used to create small burns in areas of the retina with abnormal blood vessels to try to seal leaky blood vessels.

Laser Treatment

Vitrectomy - Removal of the blood-filled vitreous and replacing it with a clear fluid to maintain the normal shape and health of the eye.

Anti-Angiogenic Drugs - The newest form of therapy currently in development is the use of anti-angiogenic therapeutics. These new drugs are being researched based on the theory that stopping the formation of new blood vessels will short circuit the problem before it gets to be a problem. Current drugs on the market include Macugen and Lucentis as mentioned earlier.