A laser is an instrument that produces a pure, high-intensity beam of light energy. The laser light can be 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.
Lasers are commonly used to treat the following eye conditions :

Diabetic retinopathy.

Diabetes causes circulation problems throughout the body, including the eyes, nerves, and kidneys. The retinal blood vessels are usually like pipes, bringing blood into and out of the back of the eye. In diabetes, however, the vessels may leak, causing the retina to swell and not work properly (diabetic macular edema). Vision is affected when the swelling involves the central vision area. Laser surgery can seal the leaks, thereby preventing further vision loss.

Retinal vein occlusions.

The small blood vessels that drain blood from the retina (retinal veins) can sometimes become blocked as part of the aging process. 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. Other times, new blood vessels may grow and cause pain with 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.

Some people will develop aging changes in the macula, the portion of the retina responsible for our central reading vision. Most will experience the less harmful dry type, which usually causes minimal visual changes. The more severe, or wet type, causes the macula to swell with fluid and blood. Symptoms of wet macular degeneration include painless blurred or distorted vision. Urgent treatment can often prevent or delay vision loss in some patients with this wet type.

Ocular histoplasmosis.

Most people in the Kentuckiana area have been exposed to histoplasmosis, a tiny plant-like organism (fungus) that causes an asymptomatic or viral-type illness early in life. There are often scars left behind in the eye and lungs that usually cause no symptoms. Some patients will develop new blood vessels adjacent to an old macular histoplasmosis scar. These vessels usually cause painless blurring or distortion. Urgent treatment can control these leaking vessels, often preserving central vision.

Retinal breaks and detachment.

The retina lines the back of the eye like wallpaper. Retinal tears or holes can occur from congenital retinal thinning, as part of aging, or following cataract surgery or eye injury. Patients will often see cobweb-like floaters or light flashes when a retinal break develops. Liquid that normally fills the central portion of the eye (the vitreous) can leak beneath the breal. lifting the retina away from the eyewall. This is called a retinal detachment, which can cause blindness if left untreated. Laser surgery around retinal tears is often able to weld the retina to the underlying eyewall. This can prevent or limit retinal detachment.