What Causes Glaucoma?
Glaucoma is generally caused by a blockage in part of the eye. This prevents fluid from draining out of the eye and increases pressure in the eye. This is also known as intraocular pressure.
Just as a basketball or football requires air pressure to maintain its shape, the eyeball needs internal fluid pressure to retain its globe-like shape and ability to see. But when something affects the ability of internal eye structures to regulate intraocular pressure (IOP), eye pressure can rise to dangerously high levels — causing glaucoma.
Unlike a ball or balloon, the eye can’t relieve pressure by springing a leak and “deflating” when pressure is too high. Instead, high eye pressure just keeps building and pushing against the optic nerve until nerve fibers are permanently damaged and vision is lost.
While high IOP often is associated with glaucoma, this eye disease can also occur when internal eye pressure is normal (normal-tension glaucoma). People with this condition have highly pressure-sensitive optic nerves that are susceptible to irreversible damage from what ordinarily would be considered “normal” IOP.
Conversely, certain people with elevated intraocular pressure known as ocular hypertension may never develop glaucoma.
Though the exact cause of normal-tension glaucoma is unknown, many researchers believe decreased blood flow to the optic nerve may be a factor. This could be caused by the narrowing of blood vessels that nourish the optic nerve or by the constrictions of these vessels (vasospasms).
Will I Go Blind?
When faced with a new glaucoma diagnosis, one predominant question comes to every patient’s mind: “Will I become blind?”
For most patients the answer is no. Needless to say, approximately 10% of people with glaucoma who do receive proper treatment end up experiencing loss of vision. When that occurs, loss of vision is irreversible and cannot be restored.
Despite that fact, proper treatment and follow-up will stabilize the disease for the vast majority of patients with glaucoma.
A major factor in the treatment of your glaucoma is you. By regularly and properly using your eye drops, a favorable outcome will be more likely.
Earlier detection seems to be one of the key factors in preventing blindness from glaucoma. Simply put, a person who has already lost some vision by the time of diagnosis is more likely to go blind than someone who is diagnosed with glaucoma prior to losing vision. It’s been estimated that 50% of people with glaucoma don’t even know they have it. Without symptoms many people do not bother to have their eyes checked for glaucoma. By the time they do go to the doctor they may already have lost their vision. This is why getting evaluated for glaucoma is so important among those at risk for this disease.
Grant WM, Burke JF. Why Do Some People Go Blind from Glaucoma? Ophthalmol. 1982;89(9):991-998.