Eye Conditions

Glaucoma

What is Glaucoma?

Glaucoma is an important cause of blindness. It is the most frequent cause of blindness in African-Americans and affects all races. Glaucoma causes progressive loss of the peripheral vision and may affect the central vision late in the course of the disease. Visual loss occurs so slowly that affected individuals are not aware that they are losing their vision.

What Causes Glaucoma?

Glaucoma is usually caused by high pressure within the eye. Pressure elevation within the eye causes damage to the optic nerve which transmits visual information from the eye to the brain. The eye may have increased pressure due to an obstruction of the normal outflow of fluid from the eye. Fluid within the eye normally is drained from a structure in the front part of the eye called the “angle”. Open-angle glaucoma, the most common type of glaucoma, occurs without visible obstruction of the angle. Closed-angle glaucoma, which occurs less frequently, is due to a narrowing of the angle and decreased flow of fluid through the narrowed angle. In either case, the fluid builds up within the eye and causes pressure to rise. This pressure can be measured by an eye doctor. Depending upon how high the pressure is, the optic nerve may be damaged over time. In open-angle glaucoma, this may take many years. In angle-closure glaucoma, which may be acute and accompanied by severe pain and loss of vision, the nerve may be damaged in several hours as the pressure can rise to extremely high levels.