Glaucoma is a disease that causes damage to the optic nerve, the structure in the eye that transmits the images that fall on the retina to the brain for visual processing. The optic nerve is made of many smaller nerve fibers. If some of these nerve fibers are damaged for any reason, a person can develop blind spots in his or her vision. Generally, glaucoma will cause development of blind spots in the vision slowly over time, and often patients will not notice these changes until the disease is advanced. Fortunately, glaucoma can be prevented and treated, so it is important to have regular eye examinations to determine if you are at risk for glaucoma.
Glaucoma is usually caused by increased pressure inside the eye. There is constant fluid being produced and drained from inside the eye. If the fluid is produced too quickly or its drainage is impaired, the eye pressure can rise. When the eye pressure rises, it exerts pressure on the optic nerve which in turn limits its blood supply. This is what causes the damage we see with glaucoma. There are several types of glaucoma, but the two main categories are open-angle and closed-angle glaucoma. Open-angle glaucoma is by far the most common. Its prevalence increases with age and generally progresses very slowly. This means the eye pressure tends to be high, but there is no blockage of the fluid drainage from the eye. Closed-angle glaucoma occurs when there is an abnormality in the angle (the structure where the fluid drains from the eye). If the angle becomes blocked, the eye pressure increases dramatically which will lead to blurry vision, extreme eye pain, halos around lights, nausea, and headache. A person can lose vision rapidly if they experience angle closure, particularly if left untreated. This is considered an eye emergency. It can be treated with prescription medications (both topical eye drops and oral tablets) and laser treatment. You should seek care immediately from your eye care provider if you develop any of these symptoms.
Glaucoma risk increases with: advanced age, tendency for high eye pressures, those with family history of glaucoma, Hispanic or African ancestry, prior eye injury, and systemic diseases like diabetes or poor circulation. Having any of these risk factors does not mean you will develop glaucoma, but it is important to be examined regularly to rule out a positive diagnosis. Glaucoma can be found with a routine eye examination, specifically tonometry (eye pressure testing) and optic nerve evaluation. If your eyes look suspicious for glaucoma, further testing (visual field testing, optic nerve scans) may be performed to monitor for changes or make the initial diagnosis. Damage that occurs from glaucoma cannot be reversed, but there are many treatments available to prevent disease progression. Most people will respond well to treatment with eye drops. Sometimes, surgical intervention is necessary if eye drops alone are not sufficient. The important thing to remember is that the only way to determine if you are at risk for glaucoma is with regular eye examinations, and that there are many treatment options should you be diagnosed.