There are two types of glaucom, closed-angle glaucoma and open-angle glaucoma. In angle-closure glaucoma, the tract used for fluid drainage is narrowed, and thus does not allow proper fluid drainage. In open-angle glaucoma, the usual drainage route for fluid is normal, but a meshwork through which the fluid flows slows drainage and causes increased levels of fluid in the eye.
Besides causing increased pressure, glaucoma can damage the optic nerve. This is the nerve that relays information from the eye to the brain. Ongoing damage to the optic nerve causes a gradual decrease in vision, eventually leading to blindness.
The test used to diagnose glaucoma is called tonometry. This test measures the pressure within the eye. A test result showing an increase in pressure may suggest a diagnosis of glaucoma. Besides measuring the pressure within the eye, tests can also identify damage to the optic nerve and measure accuracy of peripheral vision. These tests may involve examination of the eye, taking pictures of the nerve fibers within the eye, or using a laser to scan the back of the eye for signs of damage in the nerve fibers there. All of these tests can be done by an ophthalmologist.
Glaucoma treatment can include medicines or, sometimes, surgery. The most common treatment is medication that lowers the pressure within the eye. Examples include timolol (Timoptic), betaxolol (Betoptic), carteolol (Ocupress), and acetazolamide (Diamox). If medications create intolerable side effects or don’t control eye pressure, surgery may be necessary. This may involve the use of lasers. Certain operations open a passage in order to drain the excess fluid. Sometimes silicone drainage implants are used. A number of experimental procedures are also used to treat glaucoma. These may involve using collagen implants, removing debris from the meshwork through which fluid drains, or removing part of the meshwork itself.
Unfortunately, surgery is not always a cure for glaucoma. Within 2 years after surgery, many patients will still need medications to treat glaucoma. Your ophthalmologist can conduct any tests necessary to diagnose this disease. He or she can also tell you more about treatment options.