Glaucoma is an eye disease where the nerve fibers that transfer information from the eye to the brain become damaged. The disease usually has no visual symptoms in the early stages. Eventually, glaucoma damages peripheral (side) vision, and in late stages can affect central vision.
There are 3 main types:
Chronic Open Angle – most common
Normal Tension – less common
Closed Angle – uncommon
It was originally thought that an increase in eye pressure caused all types of glaucoma, but research has shown that this is not the case. While elevated pressures causes Chronic Open Angle glaucoma, in some people damage is cause with “normal” pressure. We call refer to patients as having Normal Tension glaucoma. Unfortunately in both cases there are no noticeable signs or symptoms that glaucoma is present. This is why glaucoma is often called the silent thief of sight.
In Closed Angle glaucoma, the angle between the colored part of the eye (the iris) and the clear part of the eye (the cornea) closes preventing fluid (aqueous humor) from draining normally out of the eye. Farsighted patients with shorter eyes are more likely to develop Closed Angle Glaucoma. When the aqueous can’t escape a sudden rise in pressure can occur. When the pressure rise is sudden, the eye becomes acutely painful — and this constitutes an emergency. Fortunately, Close Angle glaucoma is an uncommon situation.
The only way to determine if you have glaucoma or are at risk for either Open Angle, Normal Tension or Closed Angle glaucoma is with a thorough, complete eye exam. Screening exams where only the pressure is measured in some free screenings cannot rule out glaucoma because Low Tension Glaucoma will be missed as will those at risk for Closed Angle Glaucoma.
Regular eye exams are an important component in maintaining and monitoring your overall health. Complete exams provide the best detection and prevention of eye diseases such as glaucoma. Those with a family history of glaucoma, especially those with a sibling that has glaucoma, should be examined on a more regular basis.
Fortunately, with medication and surgery options, most glaucoma patients are able to manage their condition and prevent vision loss. The key is to catch the disease as soon as possible.