When one’s vision is compromised, his or her whole life can change in the blink of an eye. But safeguarding vision also involves understanding the various conditions that can affect eye health. Many conditions can affect a person’s vision, and one of the more common is glaucoma. Glaucoma is a group of eye disorders that can lead to progressive damage to the optic nerve. What is the optic nerve and why does it matter? The National Eye Institute (NEI) notes that the optic nerve is a bundle of more than one million nerve fibers that connects the retina to the brain. The retina is the tissue at the back of the eye that contains cells which are sensitive to light. These cells trigger nerve impulses that pass via the optic nerve to the brain, where visual images are then formed. Because its role is so significant, the optic nerve must be healthy for good vision. People who experience glaucoma can lose nerve tissue and eventually suffer vision loss. The global impact of glaucoma is significant with statistics that are real eye openers. Glaucoma is the second leading cause of blindness for people over the age of 60, although it can occur at any age. The Mayo Clinic states that many forms of glaucoma produce no warning signs and changes in vision may occur so gradually they are not detected until the condition has reached an advanced stage. The World Health Organization estimates that 4.5 million people are blind due to glaucoma. In addition, the International Agency for the Prevention of Blindness (IAPB) notes that some estimates have suggested that there will be approximately 80 million people with glaucoma by this year. If such estimates prove true, that would mean an additional 20 million cases of glaucoma were diagnosed between 2010 and 2020. Vision loss is often associated with glaucoma. However, the NEI notes that early detection and treatment can protect the eyes against serious vision loss. That makes it imperative that individuals from all walks of life learn about glaucoma, its risk factors, and how to recognize it. What are the most common types of glaucoma? According to the IAPB, primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) are the most common types of the condition. POAG is the most common form, affecting about three million Americans, according to the Glaucoma Research Foundation. POAG occurs when the eye’s drainage canals become clogged over time, and fluid cannot drain out of the eye. As a result, intraocular pressure rises and damages the optic nerve, which is responsible for transmitting signals from the eye to the brain. People with a family history of glaucoma, African Americans over age 40, and Hispanics over the age of 60 have an increased risk, says the American Optometric Association. Those with thin corneas, which is the outer layer of the eye, are also at an elevated risk of developing glaucoma. Because POAG develops slowly, its symptoms often go unnoticed. A less common type of glaucoma is called acute closure glaucoma, which occurs due to an abrupt and rapid increase of eye pressure. This is an emergency situation that requires prompt care to prevent vision loss. PACG is most common in people from southeast Asia and is associated with a greater risk of blindness than POAG. It is quick to develop and results when the drainage canals are blocked, causing a sudden rise in intraocular pressure. Symptoms are often very noticeable and may include severe and sudden eye pain; blurred vision; bright halos appearing around objects; eye redness, tenderness, and hardness; and nausea and vomiting. While there is no cure for glaucoma and vision lost from it cannot be restored, the NEI notes that treatment for early-stage POAG can effectively delay progression of the disease. An eye doctor will conduct various tests to determine if a patient is at risk for glaucoma. The Mayo Clinic says tonometry is commonly used to measure intraocular pressure. During this test, the eye surface will be anesthetized with special drops. A tonometer will be applied lightly to the cornea, indenting it slightly. The resistance will be measured and calculated to determine if pressure is present. Other tests include imaging tests that look for optic nerve damage that involve a dilated eye examination; visual field tests to check for areas of vision loss; pachymetry, which measures corneal thickness; and an inspection of the drainage angle of the eye. The effects of glaucoma cannot be reversed, but it can be caught early. Medications and lifestyle changes, like more frequent eye exams, can improve symptoms. Prescription eye drops can reduce the production of aqueous humor (fluid) in the eye and improve outflow of that fluid. Oral medications and surgery are other options as well. Vision should never be taken for granted. Appreciating your sense of sight involves scheduling routine eye exams and taking steps to protect your eyes. If you have questions or concerns about your eye health and would like help finding an eye specialist nearby, please call your provider at Family Medical Clinic of Crystal Springs, 601-892-3063. For more information about glaucoma, please visit the NEI’s website, www.nei.nih.gov.