Laser Treatment of the Retina
A laser is a pure, high-intensity beam of light energy. The laser light can be precisely focused onto the retina, selectively treating the desired area while leaving the surrounding tissues untouched. The absorbed energy creates a microscopic spot to destroy lesions or weld tissues together.
Laser surgery is usually painless; at the most it may cause temporary discomfort. It is usually performed in the Laser room while the patient is awake and comfortable. In rare cases, anesthesia is given to those patients who cannot tolerate the discomfort or to children to keep them still during treatment. The entire procedure lasts 10 to 30 minutes.
Who requires laser treatment?
Lasers are commonly used to treat the following eye conditions:
- Diabetic Retinopathy
- The retinal blood vessels are like pipes, bringing blood into and taking it out of the back of the eye. In diabetes, however, the vessels may leak, causing the retina to swell and not work properly. When the swelling involves the central area of retina vision may be affected. (This is known as diabetic macular edema.)
- Laser treatment can seal the leaks, thereby preventing further vision loss. In some patients new retinal blood vessels may grow, which will replace some of those that have closed due to diabetes. (This is known as proliferative diabetic retinopathy). This new retinal blood vessel, unlike the normal blood vessel, has a tendency to bleed inside the eye, resulting in decreased vision. Laser treatment can often prevent severe vision loss by making these new vessels regress.
- Retinal Vein Occlusion
- The small blood vessels that drain the blood from the retina (retinal veins) can sometimes get blocked (retinal vein occlusion). This is more common in patients with diabetes or high blood pressure. A retinal vein occlusion can cause the retina to swell with fluid and blood, blurring central and peripheral vision. At other times, new blood vessels may grow and cause pain as well as very high pressure inside the eye (neovascular glaucoma).
- Laser treatment can help reduce this swelling or cause the new blood vessels to disappear.
- Age Related Macular Degeneration (AMD)
- With age, some people may develop changes in the macula, the portion of the retina responsible for our central reading vision. Most people develop the dry type of AMD, which usually causes gradual vision loss. The more severe or wet type causes the macula to swell with fluid and blood. Symptoms of wet macular degeneration include painless, blurred and distorted vision. Urgent laser surgery can sometimes prevent or delay vision loss in patients with wet AMD. While the off central wet AMD patients benefit from thermal laser treatment, those with central vision problems need a prior injection of Visudyne. This is known as photodynamic therapy.
- Retinal Breaks and Retinal Detachment
- The retina lines the back of the eye like a wallpaper. Retinal tears or rips can occur as part of an aging phenomenon, or following an intraocular surgery or eye injury. When a retinal tear develops, patients often see cobweb-like floaters or light flashes. The liquid that normally fills the central portion of the eye (the vitreous) can leak beneath the tear, lifting the retina away from the eye wall. This is called a retinal detachment, which if left untreated can cause blindness. Often laser surgery around retinal tears before the fluid accumulates enables surgeons to weld the retina to the underlying eye wall. This can prevent or limit retinal detachment.
- Central Serous Chorioretinopathy (CSCR)
- Central Serous Chorioretinopathy consists of one or more ‘blisters’ of fluid (serous detachment) beneath the macula. It can cause reduction and distortion of vision, abnormal color vision, central scotoma, and temporary hyperopia or far-sightedness. Although the vast majority of cases resolve on their own, laser photocoagulation is sometimes necessary for persistent lesions and in those patients who require early visual rehabilitation.
- Ocular Tumors
- Some patients may have non-cancerous leaking vascular tumors that can cause the retina to swell and not function properly. Laser surgery can destroy some of these tumors and make the swelling go away.
How do I know that I require laser treatment?
- With retinal diseases your eye will almost always look and feel normal, even when there is bleeding and leakage in the back of the eye. Your vision may also be normal for a while despite the presence of potentially blinding eye problems.
- The only way to find out whether you need laser surgery is to have careful, dilated retinal examinations at regular intervals, often followed by a special test (called fluorescein angiography if advised by the retinal specialist), to evaluate the eye’s circulation.
After laser surgery
- There are virtually no restrictions following retinal laser surgery, but you would need to relax on the day of the treatment.
- Most patients find they can go back to their routine a day later. Invariably the doctor will advise you not to lift heavy weights for a few weeks. In some cases the doctor may advise patients to stay at home for several days. You will be required to come again for a follow-up examination in a couple of weeks up to a couple of months.
- Most patients notice no changes in vision following their laser surgery, although there may be some temporary blurring for several weeks or even months. In addition, depending on the condition being treated, some patients may notice a permanent blind spot or decrease in peripheral and night vision.
Is one session of laser treatment enough?
- The number of sessions required by a patient depends on the disease for which the laser treatment is done. It takes usually several weeks to months for surgeons to decide whether the treatment has been successful.
- Many patients require more than one session of treatment to control their problem and prevent further loss of vision.