What is Glaucoma?
Glaucoma is a group of eye diseases that affect the optic nerve which communicates vision from the eye to the brain causing vision loss. The pressure inside the eye is called intraocular pressure IOP. An increase in interocular pressure is the most common sign. A normal IOP can range from 10-21 mm Hg and is the most important risk factor for glaucoma.
What causes Glaucoma?
At the front of the eye, there is small space called the anterior chamber. Clear fluid called the aqueous humor flows in and out to nourish the tissues. When glaucoma occurs, thefluid drains slowly out of the eye and as the fluid builds up, the intraocular pressure rises in the eye. Damage to the optic nerve is result of uncontrolled pressure.
Half of the people with glaucoma are usually not aware until they experience a severe loss of vision |
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Factors associated with an increased risk of developing Glaucoma are:
- Elevated IOP
- Family history
- Ethnic background
- Smoking
- Old age
- Others
There are two main types of Glaucoma:
- In angle-closure glaucoma, the normal drainage canals within the eye are blocked. Angle–closure glaucoma can be acute (sudden) or chronic (long-lasting). In acute-angle closure glaucoma, a sudden increase in IOP occurs because of the buildup of fluid known as the aqueous humor. Acute angle-closure glaucoma is considered an emergency because optic nerve damage and vision loss can occur within hours of the onset of the problem. Chronic angle-closure glaucoma may cause vision damage without symptoms.
- In open-angle glaucoma, the drainage system remains open. Open-angle glaucoma also may cause vision damage without symptoms
Other types of Glaucoma:
- Normal (or low) tension glaucoma is an unusual and not well understood form. The optic nerve is damaged even though the IOP is consistently within normal range.
- Congenital glaucoma is a type of childhood glaucoma that usually develops soon after birth. Signs include tearing, light sensitivity, and cloudiness of the cornea. This is more common in males.
- Secondary glaucoma refers to an increased IOP that is a result of a structural problem within the eye. This secondary type may be the result of injury to the eye or other medical conditions.
- In addition, may other eye disease and systemic conditions can lead to glaucoma by increasing the IOP.
Glaucoma Symptoms
Most people with glaucoma do not notice symptoms until they begin to have significant vision loss. Small blind spots begin to develop, usually in the peripheral or side vision. Blindness from glaucoma is a result of the optic nerve being totally destroyed.
Sudden increases in IOP, especially with acute angle-closure glaucoma, may include blurred vision, halos around lights, severe eye pain, headache, abdominal pain, nausea and vomiting.
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