According to the National Eye Institute, diabetic retinopathy is the most common diabetic eye disease and is a leading cause of blindness in the United States. There are two main types of diabetic retinopathy that cause vision loss, proliferative diabetic retinopathy and macular edema.
With the incidence of diabetes increasing each year, more people will develop these eye diseases. Diabetes causes changes in the blood vessels of the body; these changes lead to the problems found in both eye conditions. Laser surgery can be used to treat both conditions.
Conditions
Diabetic retinopathy causes loss of vision in two different ways. In proliferative diabetic retinopathy, which is the most advanced form (stage 4) of the disease, abnormal blood vessels develop in the eye. These blood vessels are fragile and can easily break, causing bleeding in the eye and causing a loss of vision. In macular edema, the leaky blood vessels cause swelling in the center portion of the retina--the part that is needed for sharp vision. In many patients both conditions exist at the same time and may both need to be treated at separate laser surgery sessions.
Laser surgery to treat both diabetic retinopathy and macular edema is performed in the doctor's office. The pupils must be dilated for both laser treatments and the patient must sit at the laser; the laser setup resembles a slit lamp biomicroscope.
PRP
Scatter laser treatment, also known as panretinal photocoagulation (PRP), is used for proliferative diabetic retinopathy. The laser beam is used to cause small burns in the periphery of the retina. These burns cause the abnormal blood vessels to shrink and disappear. A compete treatment contains between 1000 and 1200 laser spots and usually is finished in several sessions. It takes a few weeks for the blood vessels to completely shrink.
A contact lens that is held against the eye is used during the laser procedure; this lens brings the periphery of the retina into better focus.
Focal Laser
For macular edema, a technique called focal laser treatment or photocoagulation is employed. Testing is done before the procedure to show the doctor exactly where the leaky blood vessels are in the macula. During the laser surgery, the specific leaky vessels are treated with the laser to seal them off and stop the leakage.
Focal laser surgery procedure is more precise than scatter laser therapy. This procedure is performed through a contact lens as well; this lens helps magnify the center portion of the retina so the physician can treat the leaky blood vessels. The swelling of the macula also takes time to improve.
Risks
The main risks associated with laser surgery for diabetic retinopathy include blind spots from the laser burns. In scatter laser therapy, the blind spots are located in the peripheral vision; after focal treatment, they are located in the central visual field.
Generally these blind spots are temporary and the patient will not notice them over time. Some people may notice some loss of night vision after scatter laser surgery.
Prevention/Solution
However successful laser surgery is in treating diabetic retinopathy and preventing any further loss of vision, this treatment is unable to retrieve vision that was previously lost because of the diabetes. This fact makes prevention of diabetes and tight management of diabetic disease all the more important. Regular eye examinations are also key in managing diabetic retinopathy.
More importantly, because there is no cure for diabetes, diabetic eye disease can recur at any time in the future. Laser treatments can be repeated as needed, but this does not correct the underlying issues.
Tags: diabetic retinopathy, blood vessels, laser surgery, macular edema, blind spots