Glaucoma is a family of diseases that cause damage to the optic nerve that if left untreated can cause loss of peripheral (side) vision and eventually central vision or total blindness. It is usually caused by increased pressure in the eye but can occur with normal eye pressure. Glaucoma is known as “the silent thief of vision” because early on in the disease process there are little or no symptoms; study data reveals that of all Americans with glaucoma fully half do not realize that they have it.
Glaucoma is more likely as patients past the age of 40 but can be seen before then. There is a genetic component to glaucoma so having a parent or sibling with glaucoma increases your risk. Glaucoma is more prevalent in African Americans, Afro-Caribbean and certain Hispanic populations. The risk is also higher for patients who use steroids, either orally, intranasal or inhaled.
The healthy eye has a pressure number between 8 and 22. The pressure is generated by the flow of fluid (aqueous humor) through the eye and back into the bloodstream. This pressure is independent of a person’s blood pressure. The fluid is made by the ciliary processes (behind the iris) and it circulates through the pupil to the trabecular meshwork (the filter in the corners of the front of the eye). Because the eye is a closed system, if the fluid cannot flow out of the eye as fast as it is produced then the pressure will rise.