What is Glaucoma?
Glaucoma is a common eye disease affecting older patients. Through rapid progression the optic nerve in the eye is damaged and vision loss occurs. There are two main types of glaucoma: open angle glaucoma and angle closure glaucoma. Open angle glaucoma is the most common form and will often go undetected during the early stages. Most patients are unaware they are suffering from a disease that could potentially take their vision because there is no pain or noticeable symptoms. With open angle glaucoma the vision will slowly decrease over time and eventually can become severe enough to cause total loss of vision. Angle closure glaucoma is the other main type of glaucoma. It is less common than open angle glaucoma but the damage to the optic nerve is more severe. Typically, the progression of angle closure glaucoma is faster, and patients will be able to notice progress because it is usually painful and vision decreases faster. This is why it is important to have regular eye exams and discuss your vision concerns with your eye doctor. Glaucoma may not be preventable but early detection may be able to slop or halt the disease.
Both forms of glaucoma can cause damage to the optic nerve, and as the disease progresses the optic fiber nerves will look “cupped” as if someone has removed the center. As the loss of tissue progresses it becomes visible to the doctor when examining the eye, and easier to diagnose as glaucoma. The loss of tissue in the optic nerve causes the vision to deteriorate over time.
Causes of Glaucoma
Glaucoma is a common disease with many treatment options available, however doctors don’t truly understand the causes. The most popular belief is that glaucoma is directly related to the abnormalities of the drainage system within the eye. This drainage system, known as the trabecular meshwork, is responsible for removing fluid from the eye. In open angle glaucoma the trabecular meshwork appears normal when examined but doctors believe there are internal problems that will cause poor drainage of the eye fluid. When the trabecular meshwork fails to allow proper drainage the pressure in the eye will increase and can cause the eye to inflate. In angle closure glaucoma, the trabecular meshwork may become blocked by the iris, abnormal blood vessels or scar tissue, which can also cause an increase in eye pressure. Increasing pressure on the eye may be one of the ways in which the optic nerve becomes damaged. Many people who suffer from open angle glaucoma have abnormally high eye pressures, suggesting that eye pressure is related to glaucoma damage. Some patients who have high pressure in their eyes do not experience glaucoma, but some patients who have no pressure will suffer from glaucoma. Doctors believe that while eye pressure plays a role in glaucoma, to a certain extent, and lowering the eye pressure can be a helpful form of treatment, other unknown irregularities in the eye or the optic nerve also play a role in disease.
Glaucoma In open angle glaucoma, there are often no clear symptoms for a patient to look for during the early stages. Eventually the disease advances into the later stages and increasing loss of vision will become apparent, a patient’s peripheral vision may be lost. Generally, the central vision remains strong but will also deteriorate over time, until a person is left with tunnel vision. Regular eye exams are encouraged so that patients can be screened for glaucoma. In angle closure glaucoma there are recognizable symptoms. A person may suffer from periods of pain, ranging from minimal discomfort to an extreme aching pain in the eye and head. During the pain, the vision may become very blurred, and for this reason people with angle closure often seek medical attention sooner, and are diagnosed with the disease earlier.
Examination for Glaucoma
In order to determine if you have glaucoma, your eye doctor will perform a series of tests to determine your visual acuity. Your best vision with glasses will be checked, along with your eye pressure and the thickness of your corneas, as thinner corneas are a risk factor for glaucoma. Your pupils will also be tested; this will help determine if your optic nerves are working properly. Your peripheral vision will also be checked either by counting fingers with the edge of your vision, or through an automated visual field examination. A slit lamp exam will also be performed in order to examine the eye and the lens. It is possible that your eyes will be dilated in order to perform a retinal exam. As glaucoma develops into moderate or advanced stages the optic nerve fibers are destroyed, causing the optic nerve to look as if it has been hollowed out. A loss of small sections of retinal nerves around the optic nerve, or small areas of bleeding on the optic nerve may also be noticeable. Additionally, if angle closure is present, your doctor may be able to see the iris or scar tissue physically blocking the trabecular drain.
If glaucoma is caught early it can be treated with eye drops to help lower the eye pressure. These medications generally work by decreasing the amount of fluid produced by the eye. Because there is less fluid produced, there is less pressure on the eye. Other forms of eye drops work by allowing the fluid to drain out of the eye. The use of these drops can slow or even stop the formation of glaucoma. In some cases, eye drops are strong enough to delay the glaucoma from becoming worse, but in cases where the eye drops are not working, you may need to undergo a form of surgery. This surgery will vary depending on the type and severity of the glaucoma. The surgical procedure to treat glaucoma is a small incision made into the drainage system of the eye. This new drainage system creates new channels to allow for a more normal flow of fluid. A trabeculectomy allows the new system to work by removing part of the eye’s current drainage system. A trabeculectomy is a common non-laser procedure performed on glaucoma patients when other treatments, like their eye drops, are not working. The procedure involves creating a leak of fluid from the eye, which flows under the conjunctiva. A small bubble will appear on the conjunctiva at the point of intersection of the cornea and the sclera where a valve will be made during the surgery.
Early detection of glaucoma can be treated, which is why it is important to visit your eye doctor regularly. The process of glaucoma can be slowed down or possibly stopped, but once vision is lost, it can’t be restored. Having a regular eye exam can possibly help prevent glaucoma or any other disease from harming your vision. If you have a family history of glaucoma, or any other eye diseases, it is vital that you seek the attention of an eye care specialist, because patients with a family history of eye diseases are more likely to develop it.