Glaucoma

What is glaucoma?

Glaucoma is a group of eye diseases in which damage to the optic nerve results in loss of eyesight. The optic nerve carries the images we see from the light-sensing retina at the back of the eye to the brain.

Glaucoma can damage nerve fibers causing blind spots to develop. People seldom notice these blind areas until considerable optic nerve damage has already occurred.

There are many types of glaucoma, but two of the more common types are: Open- angle glaucoma occurs when the optic nerve is slowly damaged, usually causing gradual loss of vision. Both eyes can be affected at the same time, although one may be affected more than the other.

Narrow-angle glaucoma is less common than open-angle glaucoma. In narrow-angle glaucoma, the iris and the lens block the movement of fluid between the chambers of the eye, causing pressure to build up and the iris to press on the drainage system of the eye. It may cause sudden, blurred vision with pain and redness, usually in one eye first; symptoms may also include nausea and vomiting.

What causes glaucoma?

A clear liquid called the aqueous humor continuously flows within the eye. The production and drainage of aqueous fluid can be compared to a sink with the faucet turned on all the time.

If the “drain pipe” gets clogged, water collects in the sink and pressure builds up. Similarly, if the drainage portion of the eye- called the drainage angle- is blocked, the fluid pressure within the inner eye may increase and that can damage the optic nerve.

Glaucoma can develop without increased intraocular pressure. In this case, decreased blood flow to the optic nerve may cause the damage.

Glaucoma can develop with certain medications such as steroids, after an eye injury, after eye surgery, from the growth of an eye tumor, or as a complication of a medical condition such as diabetes. Glaucoma can also be hereditary.

What are the symptoms of glaucoma?

If you have open-angle glaucoma, the only symptom you are likely to notice is vision loss. You may not notice the vision loss until it is severe, because your less affected eye at first makes up for the loss.

Symptoms of narrow-angle glaucoma can be very mild, often going unnoticed. You may have short episodes of symptoms, often occurring in the evening and ending by morning. However, symptoms of narrow-angle glaucoma can be severe, including sudden severe blurring of vision; severe pain in or around the eye; colored halos around lights; eye redness; or nausea and vomiting.

Can glaucoma be prevented?

Early detection and treatment are the keys to preventing optic nerve damage and blindness from glaucoma. People at high risk for glaucoma need to be checked by an eye care practitioner more frequently, even if they have no symptoms.

What is the treatment for glaucoma?

Treatment for the glaucoma focuses on preserving eyesight by slowing the damage to the optic nerve. Most treatment aims to prevent further damage to the optic nerve by lowering the pressure in the eyes.

As a rule, damage caused by glaucoma cannot be reversed. Eye drops, pills, laser and surgical operations are used to prevent or retard further damage from occurring.

Narrow-angle glaucoma can be treated with a laser iridotomy. By using a laser, a small hole is made in the iris to create a new pathway for the aqueous fluid to drain from the eye. The new drainage hole allows the iris to fall back into its normal position, restoring the balance between fluid entering and leaving the eye and lowering eye pressure.

Open-angle glaucoma can be treated with laser trabeculoplasty. This procedure works by using laser light to stimulate the body’s own healing response to lower your eye pressure. Laser trabeculoplasty improves the flow of fluid in the eye, which in turn lowers your eye pressure.

Neither the YAG laser iridotomy nor the laser trabeculoplasty will help improve the patient’s vision. The purpose of these lasers is to help lower the eye pressure and prevent vision loss.