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. The injection of anesthetic may be uncomfortable. And then you may feel a slight stinging sensation or see brief flashes of light when the laser is applied to your eye.
What To Expect After Treatment
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.
Why It Is Done
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 non-proliferative 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.
How Well It Works
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.
What To Think About
The biggest drawback to laser photocoagulation is that the laser damages some of the light-sensitive nerve cells in the retina and macula. This often results in some vision loss.
But the immediate vision loss caused by laser treatment must be measured against the more severe vision loss that could result from untreated retinopathy. For people who have diabetic retinopathy, laser photocoagulation will very likely help prevent more severe vision loss over time.
Diabetes experts agree that early detection and treatment of retinopathy can prevent many, or even most, cases of severe vision loss and blindness in people who have diabetes.
Be sure to keep your blood sugar levels low after laser treatment. Even if your eyes are better, diabetic retinopathy will keep getting worse over time if your blood sugar levels rise again.