Glaucoma is a leading cause visual impairment in the US, and can affect patients of all ages, many of who do not experience any symptoms and may not be aware that they have the disease. Glaucoma actually refers to a group of diseases that cause damage to the optic nerve as a result of increased pressure within the eye. It can also be caused by a severe eye infection, injury, blocked blood vessels or inflammatory conditions of the eye.
There are two main types of glaucoma, open-angle and closed-angle. Open-angle glaucoma is the most common type of glaucoma and results when fluid in the eye does not drain properly through the normal drainage channels, known as the trabecular meshwork. Open angle glaucoma usually occurs gradually and slowly, and is dangerous because it often does not cause symptoms until it is extremely advanced. Closed-angle glaucoma typically results from buildup of pressure in the eye behind the iris, preventing normal fluid circulation through the eye. Closed-angle glaucoma can occur suddenly, which is a medical emergency and requires prompt treatment to prevent blindness.
Many patients do not experience any symptoms during the early stages of glaucoma, as there is often no pain or discomfort and the vision loss can be subtle and gradual. This makes it difficult for many patients to know if they have the disease, and to tell if it is controlled by treatment. As glaucoma progresses, patients may experience a loss of peripheral or side vision, but when this becomes noticeable it usually means the disease is very advanced.