All About Glaucoma
What is Glaucoma?
Glaucoma is a disease that causes vision loss due to damage of the optic nerve. The optic nerve is responsible for carrying the eye’s visual stimulus to the brain. While vision lost to glaucoma cannot be restored, the goal of treatment is to slow or stop the progression of the disease.
How Does Glaucoma Occur?
The normal eye is continuously producing a fluid called aqueous humor. This fluid is responsible for keeping the eye nourished and filled to its proper size. In high pressure glaucoma, the drainage of aqueous humor is compromised, causing a fluid build-up that increases pressure inside the eye. This pressure leads to ganglion cell death and can be detected by checking a person’s vision for blind spots or peripheral vision loss. In normal pressure glaucoma, the ganglion cells die as well, but it is not directly related to high pressure in the eye. Although vision loss is not immediately noticeable, over time, complete blindness can occur as there will be no effective transfer of visual stimuli to the visual cortex of the brain.
Are there different types of Glaucoma?
The two main types of glaucoma are classified by how the eye’s drainage angle is affected. The most common type in the United States, primary open-angle glaucoma, occurs when the drainage angle is not directly blocked, but has lost the ability to drain effectively. This type of glaucoma causes no pain and is frequently without symptoms until it is very advanced. The other main type, angle-closure glaucoma, occurs when a person’s iris (the colored part of the eye) is unusually close to the drainage angle which leads a direct blockage. In about a third of cases, that type of blockage can happen suddenly. Acute episodes can be very painful and frequently require emergency medical attention. In most people, however, angle-closure glaucoma is chronic and builds up more slowly. As there are no symptoms, many do not discover they have glaucoma until they experience an acute attack, or until vision loss is severe in later stages.
What are the signs of an acute angle-closure glaucoma attack?
According to the American Academy of Ophthalmology, the symptoms of an acute angle-closure glaucoma attack are:
- Sudden blurry vision
- Severe eye pain
- Nausea and/or vomiting
- Rainbow-colored halos or rings around lights