Thursday, April 29, 2010

Glaucoma


reviewed by Fu OD

Glaucoma is a disease that damages the eyes' optic nerves. Damage does not become noticeable until significant damage has occurred and if not treated could lead to severe vision loss or even blindness. Glaucoma is usually present with high intraocular pressure, pressure in the eyes, and results in a loss of peripheral vision. Early detection through eye exams will greatly help slowing down the disease.

Forms of Glaucoma

  • Normal-tension Glaucoma - occurs when there is optic nerve damage and loss of vision even with intraocular pressure within a normal range
  • Angle-closure Glaucoma - Increase in eye intraocular pressure due either to too much fluid being produced in the eye or to fluid not being able to exit the eye due to a blockage of the meshwork inside the eye. This can cause pain, headaches, nausea, red eyes, blurred eyes and vision loss. According to the NEI, "This is a medical emergency. If your doctor is unavailable, go to the nearest hospital or clinic. Without treatment to improve the flow of fluid, the eye can become blind in as few as one or two days."
  • Secondary Glaucoma - can form after eye surgeries or from certain medical conditions like diabetes
  • Congenital Glaucoma - present at birth due to birth defects that hinders the flow of fluid out of the eye that causes cloudy, white eyes and sensitivity to lights
  • Open-Angle glaucoma - the most common type of glaucoma, occurs when fluid drainage from the eye is hindered, causing intraocular pressure to increase above normal, thus damaging optic nerves and eventually leading to vision loss. Usually peripheral (side) vision is damaged first leading to tunnel vision and in time to blindness if not properly treated and monitored

Glaucoma Symptoms and Detection

Warning signs of glaucoma are different for each form. Glaucoma is usually not noticeable until significant damage has been done to the optic nerves. With open-angle glaucoma, the most common form, an increase in intraocular pressure and loss in peripheral vision are key signs. A tonometer is an instrument that measures pressure inside the eye. It can show abnormal pressure that causes damage to optic nerves. A dilated eye exam uses drops to widen the pupils to allow an eye care professional to check optic nerves for changes. A visual field test helps an eye doctor tell if any peripheral vision loss has occurred, which is a sign of glaucoma. A nerve fiber analyzer is an instrument that very precisely examines the nerve fibers of the optic nerve for damage.

Glaucoma Example

Glaucoma Treatment and Prevention

he most conventional treatment for glaucoma is medicine that is taken as a pill or as eye drops. The medicine has one goal and that is to decrease eye pressure. These medications either decrease the amount of fluid produced or help the eye remove fluid easier. Glaucoma medication might interfere with other medication so it is a good idea to consult your doctor and let them know about all of the medications you are taking. There are several different types of glaucoma medication so your doctor may want to try another one if it conflicts with medication you are currently taking or causes unwanted side effects. For most people medicine is enough to control glaucoma. For others, surgery is the better option. Laser trabeculoplasty is another option for decreasing pressure in the eyes. In this option, an Ophthalmologist sends a laser beam into the meshwork where fluid drainage occurs,called the trabecular meshwork. The process increases the drainage area and lowers pressure. With Argon Laser Trabeculoplasty (ALT), the surrounding tissue in the meshwork is damaged and usually requires another session after a few years. Sometimes medication must also still be taken. With Selective Laser Trabeculoplasty (SLT), a specially designed laser emits a low-energy laser light that targets only melanin-containing cells in the trabecular meshwork. The laser is heated only enough to affect the opening of the meshwork and adjacent areas are not damaged. This allows for multiple re-treatments. Endoscopic CycloPhotocoagulation (ECP) is another process to help alleviate eye pressure if medication and laser trabeculoplasty are not effective. Unlike laser trabeculoplasty, ECP uses lasers to target the ciliary body that produce fluid. This causes less fluid to be produced and in effect lowers pressure. Lowering the risk of glaucoma or at least slowing down the progressive damage to optic nerves is the best preventive measure. It is important to get routine check ups because glaucoma is unnoticeable at first. Certain risk factors to watch out for include race, medical disorders, and family medical history. Glaucoma is more common in African Americans and Hispanic patients, especially with increasing age. People with diabetes or who have had eye surgery are also more likely to have glaucoma. A family history of glaucoma increases the risk that you could have glaucoma. If any of these factors relate to you, then you should definitely go for more frequent eye exams.

For more information on glaucoma visit your eye care doctor or visit http://www.glaucoma.com/ or http://www.nei.nih.gov for more research. Materials on this page have been researched from the national Eye Institute.

No comments:

Post a Comment