Thursday, April 19, 2007

Glaucoma - a thief in the night

This is an eye disease which is little understood by the general public. It's a disease of the optic nerve, which usually affects the peripheral vision first then gradually going centrally. A rise in intraocular pressure is usually but not always noted.

Glaucoma may be acute or chronic.

In acute glaucoma, there is a sudden increase in intraocular pressure (the pressure inside the eyeball), causing severe eye pain, headache, nausea, vomiting, blurring of vision and iridescent vision (seeing rainbows around lights). This is considered as a relative ophthalmologic emergency, and it is imperative to see an ophthalmologist at this point so that management of the glaucoma can be instituted immediately.

In chronic glaucoma, there is no sudden increase in intraocular pressure, hence, the signs and symptoms are a lot more subtle. There may be occasional headaches or eye pain, but generally the patient does not really feel a pressing need to see a doctor because these symptoms are not that severe or get relieved with minor measures like over the counter medications. Or they may not even feel any symptoms at all. The tragedy of chronic glaucoma is that patients do not know that they have this disease until they have already lost a significant amount of peripheral vision.

It is important to remember that since the optic nerve gradually loses axons in this disease, any vision loss is considered permanent. That's why an early diagnosis is important so that early intervention can be done and the progression of the disease can be minimized.

Current recommendations for people less than 45 years old and without risk factors for glaucoma to have an eye check at least every 4 years, and those above 45, at least every 2 years. If you have known risk factors for glaucoma, it's recommended that an eye exam should be done at least every 2 years if you're under 45 and every year if you're above 45. The following are considered as risk factors: Family history, myopia (nearsightedness), previous eye injury, low blood pressure, African descent, diabetes, long exposure to cortisone. (Previous info from The Glaucoma Foundation, website .)

It is also important to note that glaucoma is a disease that is controlled, not cured. That means that patients should visit their eye doctors at periodic intervals so that the treatment regimen can be reassessed accordingly.

How is diagnosis made? The ophthalmologist screens for glaucoma by looking at the optic nerve through an ophthalmoscope or through a special lens and a slit lamp. He also measures the intraocular pressure using a tonometer. Then gonioscopy, which allows him to see the "angles" of the eye is done to determine if it's an open angle or an angle closure type of glaucoma. This is important because the type of treatment is dictated by the type of glaucoma. Perimetry is then done to assess the peripheral visual function.

There are 3 basic treatment options available for glaucoma. These include medical treatment - with use of eyedrops and sometimes oral or IV medications, laser treatment and surgical treatment. The type of treatment is dependent upon the stage and the type of glaucoma.

It is important that patients undergoing glaucoma treatment understand that a careful and periodic monitoring of their disease by a qualified ophthalmolgist is a must in order that treatment plans are reevaluated and updated as needed, for maximum suppression of disease progression.

Should you have further questions, please do not hesitate to leave a comment and an email.

No comments: