What is Glaucoma?
Glaucoma is an eye disease that impairs vision in older patients. The optic nerve becomes damaged which results in vision loss. The two main type of glaucoma are: open angle glaucoma and angle closure glaucoma. Open angle glaucoma is the most common form of glaucoma and is often unnoticed or untreated in the early stages. Most patients do not realize they are suffering from open angle glaucoma because it is virtually painless. That is why it is important to have regularly scheduled eye examinations to monitor for diseases such as glaucoma that can slowly become more damaging over time. Angle closure glaucoma is the other main form of glaucoma that impacts older patients but is much less common than open angle glaucoma. Angle closure glaucoma can accelerate much faster and cause more severe damage to the optic nerve.
Regardless of the type of glaucoma that a patient has, the damage to the optic ultimately has the same impact. The optic nerve fibers are slowly destroyed causing the optic nerve to appear as if someone has just scooped out the insides. As the loss of tissue progresses, it becomes more noticeable to the doctor examining the eye that the disease is present. The progressive loss of the optic nerve tissue causes the vision to be decreased. Ultimately, a patient may go blind from glaucoma.
What Causes Glaucoma?
Glaucoma is a well known eye disease that affects many senior eye patients around the world, yet the exact cause of glaucoma is still relatively unknown. Studies show that the trabecular meshwork, or drainage system of the optic nerve, may be the cause of glaucoma. In patients with open angle glaucoma the trabecular meshwork looks normal from the outside but many believe there are internal abnormalities that cause drainage problems. If the trabecular meshwork drain fails to allow the fluids to leave eye then the eye pressure will increase causing the eye to inflate. In angle closure glaucoma, the trabecular meshwork can become blocked by the iris, abnormal blood vessels or scar tissue, which can cause increase in the eye pressure.
The increasing eye pressure may be one of the ways the optic nerve becomes damaged. Many patients who suffer from open angle glaucoma have high eye pressures which suggest that the eye pressure may have a direct relation to the causes of glaucoma. However, not all patients who suffer from high eye pressure suffer from glaucoma and patients who have normal eye pressure suffer from glaucoma. Doctors believe that eye pressure plays a role in the disease and treatment can help to decrease the impact glaucoma has on vision loss.
What are the Symptoms?
Open angle glaucoma patients often have no noticeable symptoms that would lead them to believe that they have glaucoma. As the disease progresses vision loss becomes apparent. First the peripheral vision begins to decrease while the center vision remains strong. Over time, the central vision will also be lost. Angle closure glaucoma patients have recognizable symptoms. An angle closure glaucoma patient may suffer from periods of pain, ranging from minimal discomfort to severe pain in the eye and head. Each episode of pain may cause the vision to become blurred. For this very reason patients with angle closure glaucoma often seek out medical attention sooner then an open angle glaucoma patient.
In order to determine if you have glaucoma, your eye doctor will perform a variety of eye tests. A thorough evaluation will be required before a diagnosis is made. Visual acuity, a refraction, and best vision with glasses will be checked. Eye pressure will be measured to determine if the level is normal. The thickness of your cornea will also be checked because thinner corneas are a risk factor for glaucoma. Peripheral vision will be checked because of the role it plays in glaucoma. The drainage of the trabecular meshwork will be examined with a special contact lens called a gonioscopy lens. Your eyes may be dilated to help the doctor view the lens and the back part of the eye and examine the optic nerve carefully. A retinal exam may also be performed during the dilated examination. Photographs of your optic nerves or computer scans of the optic nerve shape may also be taken.
As glaucoma develops into the moderate or advanced stages of the disease, optic nerve fibers are destroyed, causing the optic nerve to look as if has been hollowed out. Your doctor may also be able to see the loss of small sections of retinal nerves around the optic nerve, or small areas of bleeding on the optic nerve. Additionally, if angle closure is present, your doctor may be able to see iris or scar tissue physically blocking the trabecular drain.
Treatment for Glaucoma
Early glaucoma treatment normally involves eye drops that help to lower the eye pressure. These medications commonly work by decreasing the amount of fluid produced by the eye, with less fluid being produced there will be less pressure in the eye. Other forms of eye drops work by allowing fluid to drain out of the eye(s). The use of these medicated eye drops can slow or halt the progression of glaucoma.
In some cases eye drops alone are not strong enough to delay the glaucoma from becoming worse over time. In cases where eye drops are not working, doctors may suggest a form of surgery. The doctor will go over which surgery is suitable for your eyes depending on the type or glaucoma and the level of severity it is currently at.
Prevention of Glaucoma
Once vision is lost with glaucoma, it cannot be restored. The best way to help prevent glaucoma is to visit your doctor for regular annual eye exams to ensure that your eyes are in a healthy condition. With regular annual eye exams glaucoma can be caught before vision becomes impaired. For this reason, everyone should have regular annual eye exams to screen for glaucoma. If you have a family history of eye diseases and glaucoma, you should have eye exams more frequently as you may be at a greater risk for glaucoma.