Glaucoma is a disease that affects the optic nerve in the back of the eye and can reduce your field of vision. The optic nerve, about the size of your little finger, carries over a million nerves that convey images from your eye to your brain. Pressure on the delicate nerve can reduce your field of vision.
Called the “sneak thief” of sight, glaucoma has no symptoms, even while damage is being done. Glaucoma tends to run in families, so if you have a relative who had vision loss or used eye drops daily, be sure to have an eye exam to rule out glaucoma. Glaucoma is also more prevalent in African-Americans. Early detection is the key to protecting your vision from damage caused by glaucoma.
The most common type of glaucoma, Open Angle Glaucoma (OAG), occurs when there is either a sustained increase in fluid production or a decrease in fluid drainage. With this imbalance in fluid flow, there is an increase in the intraocular pressure, which in turn reduces the blood flow in the sensitive tissues of the optic nerve. Over time, as the optic nerve fibers are destroyed, peripheral (side) vision is lost.
There is no cure for glaucoma - yet. However, medication and/or surgery (both incisional and laser) can slow or prevent further vision loss. The appropriate treatment depends upon the type of glaucoma and other factors. Early detection is vital to preserving vision.
There are two major types of Glaucoma: primary open-angle glaucoma, and angle-closure glaucoma.
If the eye's draining process gradually begins to weaken, pressure will build and begin damage to the optic nerve. This process is known as Primary open-angle glaucoma; it is the most common type of glaucoma. Primary open-angle glaucoma is painless and does not cause vision change at first. Regular eye exams are important to find early signs of damage to the optic nerve.
Depending on the anatomy of your eye, you may be at risk for angle-closure glaucoma. This type of glaucoma is caused in eyes where the iris is very close to the drainage angle. Due to location of the iris and drainage angle, eye pressure can rise very quickly if the draining process begins to weaken. Once the drainage angle is completely blocked, a person will experience an acute attack.
• People Over 60 are six times more likely to get glaucoma
• Glaucoma is the leading cause of blindness among African-Americans. It is six to eight times more common in African-Americans than in Caucasians
• Family history increases risk of glaucoma four to nine times. The most common type of glaucoma, primary open angle glaucoma, is hereditary
• Eye Injury may cause secondary open angle glaucoma. This type of glaucoma can occur immediately or years after the injury
Glaucoma treatment includes medicated eye drops and/or pills alone or in combination with laser or incisional procedures. Your doctor may prescribe one or more kinds of eye drops to control your inner eye pressure.
Regularly scheduled eye exams to measure the effects of the drops on your pressure will be required.
Laser procedures may be recommended in combination with drops or when drops have failed to control your pressure and prevent ongoing damage. These procedures may include YAG, SLT or Aragon lasers. These procedures are usually done in the BVA office.
Other surgical procedures include ECP (endocyclophotocoagulation), Ahmed valve insertion, trabeculectomy and trans-scleral cyclophotoablation. These procedures are usually performed in a hospital or surgery center.
Regular glaucoma check-ups include two routine eye tests: tonometry and ophthalmoscopy.
However, if the pressure in the eye is not in the normal range or if the optic nerve looks unusual, then one or more special tests may be recommend.
Measures the inner pressure of the eye. The doctor or technician will use a special device, called a tonometer, to measure the eye’s pressure. Numbing drops are used to keep you comfortable. The pressure will be expressed as a number from 10 to 20 or more.
Examines the health of the inside of the eye, especially the optic nerve. Dilating drops will be instilled to allow the doctor a larger view of the inside of your eye. The drops will take 20-3– minutes to fully take effect. In a darkened room, the doctor will use a bright light to magnify and view your eye using an ophthalmoscope.
Also called a visual field test, maps the boundaries of your field of vision from peripheral (side vision) to central. During this test, you will be asked to look straight ahead and to indicate when a moving light passes your field of vision. Glaucoma damage can be determined by changes to a healthy field of vision.
A painless eye test that allows the doctor to view the angle where the iris meets the cornea to see if the normal flow of eye fluid is open or closed. Abnormal flow may result in increased eye pressure.
Optical Coherence Tomography uses light-wave reflection and back scattering to create a computerized image of the retinal nerve fiber layer. These early changes to the delicate retinal layers can precede changes to visual field loss. Once vision is lost to the visual field, it cannot be restored.