Glaucoma - Its Cause And Treatment

Glaucoma! A condition feared by many, yet understood by few. It steals your eyesight like a thief in the night. Before you realize you have a problem the damage can be permanent and, untreated, can lead to blindness.

What can you do to minimize the problem?

Well, since there is no cure, your first priority must be early diagnosis. Regular checkups by your optometrist or ophthalmologist is the first step in detection and control. An eye examination at least every two years will help in detecting and controlling glaucoma before it causes permanent, irreversible damage.

What is glaucoma?

A leading cause of blindness, glaucoma is actually a group of disorders caused by obstruction of the flow of fluid within the eye, aqueous humor, which is produced continuously. Within the eyeball when the aqueous humor does not drain properly. As the optic nerve deteriorates, blind spots develop and there are changes in vision.

Types of glaucoma

There are four major types of glaucoma: open angle (chronic); closed angle (acute); congenital, and secondary. All types result in damage to the optic nerve, caused by increased pressure.

Acute glaucoma most often occurs after the age of 40 as the lens of the eye gradually becomes larger, resulting in narrowing of the angle between the iris and the cornea. Eventually a blockage develops, obstructs the exit of the aqueous humor and causes a sudden increase of pressure within the eye. The pressure causes severe eye pain, headaches and nausea to the point of vomiting. Lights appear to have blurred halos around them. When experiencing such symptoms it is essential to see an eye doctor immediately. Blindness can result if acute angle glaucoma is not treated promptly. These symptoms develop rapidly in the elderly, particularly in the far-sighted. Attacks can develop without any warning, especially in dim light conditions when the pupils are dilated. The excessive use of drops to dilate the eyes may also provoke attacks.

The most common type of glaucoma is chronic or open angle glaucoma. The drainage angle is not blocked by the iris as in acute glaucoma and the cause has not been clearly established. Both eyes are usually affected and, with the passage of time, the fibers of the optic nerve and the retina are damaged by the constant increase in pressure. This type of glaucoma is most often marked by a complete lack of symptoms. There are no warning signs, no pain, and loss of peripheral vision is so gradual that it usually goes unnoticed until considerable damage has occurred. If the condition is not treated, blindness will result in a few years. The only way to detect this type of glaucoma in the early stages is through regular eye examinations by a qualified professional.

The cause of secondary glaucoma is associated with other diseases, both eye diseases and systemic diseases, and the use of corticosteroids. Congenital glaucoma is a birth defect that requires surgery to correct.

Risk Factors and Treatment

For chronic glaucoma, the most common and most controllable of the glaucomas, the risk factors are a family history of glaucoma, diabetes, near-sightedness and age (40 plus). There is a greater incidence - and symptoms develop at an earlier age - among persons of African ancestry. Estimates of cases of chronic glaucoma among persons 40 years or older range around one or two percent (1% - 2%) with about 25% undetected. Oral medications or eye drops prescribed by a physician are commonly used to treat this type of glaucoma by reducing the amount of aqueous humor or increasing its drainage from the eye, thus decreasing the amount of intraocular pressure.

The risk factors for acute glaucoma include aging, far-sightedness, family history and stress, with overuse of medications such as atropine or eye-dilation drops as additional causal factors. For most cases there is no prevention for the development of glaucoma, but if detected early, vision loss or early blindness may be prevented. Careful use of dilating eye drops and systemic medications may prevent acute attacks in high risk individuals.

The medications used in the treatment of glaucoma are usually well tolerated and effective in keeping the condition under control. Such minimal side effects as headaches, blurred vision or stinging of the eye usually clears up in a short period of time. For effective treatments it is essential to take the medications as prescribed and continue to have your eyes examined regularly to monitor the medication's effectiveness.

If you are unsure how to administer your eye drops, ask your doctor or pharmacist to demonstrate the proper technique. Remember, any loss of vision occasioned by glaucoma is permanent. It cannot be restored. Don't neglect its treatment.

For more information on the subject contact Glaucoma & Vision Impairment Society of Canada.