Etiology: Glaucoma is the name for a group of eye diseases that damage the optic nerve. The optic nerve carries information from the eye to the brain, in the back of the eye. When the nerve is damaged vision loss will occur. This loss happens over a long period and can even go unnoticed. Once the damage is done there is no way to reverse it. Just slow done the continuing damage and treat the symptoms. This disease is usually genetic. Glaucoma is caused by a buildup of pressure inside the eye. At first, people with glaucoma lose peripheral vision. If the disease is not treated, vision loss will continue. Over time this can then lead to total blindness. Glaucoma is the second leading cause of blindness behind cataracts. There are many types of glaucoma but the main two are open-angled glaucoma and closed-angle glaucoma.
Open-angled glaucoma or primary/chronic glaucoma is the most common affecting three million Americans. About 90% of glaucoma cases in the United States are open-angled glaucoma. In this type of glaucoma, the optic nerve is damaged bit by bit, and is a lifelong condition. This slowly leads to the loss of eyesight. One eye may be affected more than the other. Sometimes much of the eyesight may be lost before even notice. This type of glaucoma is the result of slow clogging in the drainage canals which increases pressure in the eye. “Open angled” means there is a wide and open angle between the iris and the cornea.
Closed-angled glaucoma or acute/narrow-angled glaucoma is less common than open-angled glaucoma. About 10% of all glaucoma cases in the United States are closed-angled. In this type of glaucoma, the colored part of the eye, iris, and the lens block the movement of fluid between the chambers of your eye. This causes pressure to build up and the iris to press on the drainage system of the eye. This type of glaucoma develops very quickly and demands immediate medical attention. Unlike open-angled glaucoma, closed-angle glaucoma has noticeable symptoms. “Close-angle” means there is a closed or narrow-angle between the iris and the cornea, unlike open-angled glaucoma.
Symptoms: In open-angled glaucoma, the only noticeable symptom is loss of vision. It may not be noticed until it is very serious. This is because at first the eye that is not affected makes up for the vision loss. Side vision, or peripheral, vision is often lost before central vision. Symptoms of closed-angled glaucoma can be mild to extremely painful with symptoms like blurred or a decrease in vision that only lasts for a short time. More severe signs of closed-angled glaucoma include longer-lasting episodes of blurred vision, seeing halos around lights, red eyes, pain in or around the eye, nausea and vomiting, and dilated or oval pupils.
Treatment: Once vision is lost there is no way to recover it, so treatment is aimed at preventing any further damage. Glaucoma is usually treated with drugs, laser, or conventional surgery. All of these treatments are aimed at decreasing the built-up pressure in the eye by increasing the drainage or decreasing the production of fluid in the eye. Most medicines used to treat glaucoma are lifelong supplements. These can be pills or eye drops. Some surgeries that help treat glaucoma are trabeculectomy and surgical implants. Although both surgeries and drugs have a high success rate at treating open-angled glaucoma, there will be long-term care and regular treatments to continually treat. Laser treatment is usually performed on people with closed-angled glaucoma and is a preventive treatment, so there is less long-term care.
References
http://www.webmd.com/eye-health/understanding-glaucoma-treatment
http://www.effectivehealthcare.ahrq.gov/search-for-guides-reviews-and-reports/?pageaction=displayproduct&productID=1395
