A complex eye disease, glaucoma is not simply an elevated intraocular pressure. Glaucoma is actually a broad term that is used to characterize a range of eye conditions that damage the optic nerve and potentially cause loss of vision. Glaucoma, therefore, is a disease of the optic nerve, the vital nerve bundle that carries images to your brain so you can see.
Glaucoma usually affects both eyes but can progress more rapidly in one eye than in the other. Involvement of just one eye primarily occurs when glaucoma is brought on by factors such as a prior injury or the use of steroids in that eye.
How Glaucoma Works
The eyeball is basically a rigid sphere filled with aqueous humor. In the normal eye, there is a constant production and drainage of this fluid. This production and drainage is balanced so as to maintain a “normal’ intraocular pressure (IOP). As the total amount of fluid within the eye increases so does the pressure. Many people relate glaucoma to increased pressure inside the eye, although that is not the only cause, but is a common cause of glaucoma. The higher the pressure inside the eye, the greater the chance of damage to the optic nerve.
As a rule, damage caused by glaucoma cannot be reversed. Eye drops, pills and laser and surgical operations are used to prevent or slow further damage from occurring. With any type of glaucoma, annual examinations are very important to prevent vision loss. Because glaucoma can worsen without your being aware of it, your treatment may need to be changed over time.
Glaucoma is usually controlled with eye drops administered several times a day, sometimes in combination with pills. These medications decrease eye pressure, either by slowing the production of aqueous fluid within the eye or by improving the flow leaving the drainage angle. For these medications to work, you must take them on a regular and continuous basis. It is also important to tell all of your doctors about the eye medications you are using. Glaucoma medications can have side effects. You should notify your eye doctor immediately if you think you may be experiencing side effects.
Laser surgery treatments may be effective for different types of glaucoma. The laser is usually used in one of two ways. In open-angle glaucoma, the drain itself is treated. The laser is used to enlarge the drain (trabeculoplasty) to help control eye pressure. In angle-closure glaucoma, the laser creates a hole in the iris (iridotomy) to improve the flow of aqueous fluid to the drain.
When operative surgery is needed to control glaucoma, your ophthalmologist, a surgery trained eye MD uses miniature instruments to create a new drainage channel for the aqueous fluid to leave the eye. The new channel helps to lower the pressure.
Though serious complications of modern glaucoma surgery are rare, they can occur, as with any surgery. Surgery is recommended only if your ophthalmologist feels that it is safer to operate than to allow optic nerve damage to continue.