What is laser photocoagulation for diabetic retinopathy?

Laser photocoagulation uses the heat from a laser to seal or destroy abnormal, leaking blood vessels in the retina. One of two approaches may be used when treating diabetic retinopathy:

Focal photocoagulation.

Focal treatment is used to seal specific leaking blood vessels in a small area of the retina, usually near the macula. The ophthalmologist identifies individual blood vessels for treatment and makes a limited number of laser burns to seal them off.

Scatter (pan-retinal) photocoagulation.

Scatter treatment is used to slow the growth of new abnormal blood vessels that have developed over a wider area of the retina. The ophthalmologist may make hundreds of laser burns on the retina to stop the blood vessels from growing. The person may need two or more treatment sessions.

Laser photocoagulation is usually not painful. You may feel a slight stinging sensation or see brief flashes of light when the laser is applied to your eye.

Laser treatment may not restore vision that has already been lost. But when it is done in a timely manner, laser treatment may reduce the risk of future vision loss.

Laser photocoagulation burns and destroys part of the retina and often results in some permanent vision loss. This is usually unavoidable. Treatment may cause mild loss of central vision, reduced night vision, and decreased ability to focus. Some people may lose some of their side (peripheral) vision. But the vision loss caused by laser treatment is mild compared with the vision loss that may be caused by untreated retinopathy.

Rare complications of laser photocoagulation may cause severe vision loss. These include:

• Bleeding in the eye (vitreous hemorrhage).
• Traction retinal detachment.
• Accidental laser burn of the fovea (a depression in the central macula that contains no blood vessels). This results in severe central vision loss.

Call your doctor now or seek immediate medical care if:

• You have vision changes.
• You see new flashes of light.

Watch closely for changes in your health, and be sure to contact your doctor if:

• You see new or worse floaters.
• You do not get better as expected.

Laser photocoagulation is usually done as an outpatient procedure using a local or topical anesthetic that affects only the eye. You do not have to stay overnight in a hospital.

You will need someone to drive you home from the doctor's office or clinic after the procedure. Eyedrops are used to widen (dilate) your pupils before the procedure. And your eyes will remain dilated for several hours afterward. Wear sunglasses to keep bright light out of your eyes while they are still dilated.

Your vision may be blurry and your eye may hurt a little for a day or two after the treatment.

Be sure to keep all follow-up appointments with your doctor and report any changes in vision that you notice. Follow-up treatment can make a big difference in keeping your vision for the long term.

The doctor puts medicine in your eye to numb it. You are given eyedrops that widen (dilate) your pupils. You may also get medicine to help you relax. Your eyelids are held open during treatment.

Many people don't feel pain during this type of laser treatment. Some people feel mild pain or discomfort. You may feel a slight sting or see brief flashes of light when the laser is applied to your eye.

Laser photocoagulation is done to reduce the risk of vision loss caused by diabetic retinopathy. It is most often used to stabilize vision and prevent future vision loss rather than to improve vision loss that has already occurred. (Sometimes focal photocoagulation for macular edema caused by nonproliferative retinopathy can help restore lost vision.)

Laser photocoagulation may be used to treat and prevent further progression of:

• Macular edema. Focal photocoagulation is sometimes used in these cases.
• Proliferative retinopathy. Scatter (pan-retinal) photocoagulation is used to treat proliferative retinopathy.