Glaucoma, the leading cause of blindness and visual impairment in the United States, is an eye disease that can lead to a permanent loss of vision.
This disease has been labeled the “Sneak Thief of Sight” because in its most typical form, there are no symptoms — no pain, no swelling, no redness. Patients with glaucoma may not notice symptoms until vision has been permanently lost.
Glaucoma is a disease process that progressively damages the optic nerve, the structure that transmits the visual stimulus from the eye to the brain. Most patients with glaucoma have elevated intraocular pressure.. Every eye has fluid, called aqueous humor, which is constantly being produced as well as constantly being drained.
In a glaucomatous eye, this fluid does not drain properly resulting in an increase in the pressure inside the eye. This increased pressure destroys vision gradually, usually starting with the peripheral (side) vision. If left untreated, it will lead to eventual blindness by destroying the optic nerve. With early diagnosis and treatment, useful vision may be preserved.
The only known treatment for glaucoma is to lower the intraocular pressure. Typically we attempt to lower the intraocular pressure with eye drop medications. This works in most cases but sometimes we have to perform a surgery on the eye to lower the pressure.
There are four types of Glaucoma
Glaucoma occurs when the clear fluid that keeps the eye formed and nourished is unable to drain from the eye through the drainage system (Trabecular meshwork). Because the fluid is unable to drain, pressure builds in the eye and over time may cause damage to the optic nerve and lead to vision loss. Medication, laser surgery, or other glaucoma surgeries may be used to lower and control the intraocular pressure.
When medication and laser treatments cannot control the eye pressure adequately, surgery is usually recommended. Glaucoma filtering surgery (Trabeculectomy) is the most common.
Your doctor will make a small flap in the sclera (white part of the eye). A filtration bleb, or reservoir is created under the conjunctiva (thin, clear coating over the sclera) . The bleb looks like a blister or bump on the white part of the eye but is usually hidden by the upper lid. The fluid inside the eye can then drain through the flap, collect in the bleb where it is reabsorbed into the body.
After the bleb is constructed, the incision is closed with stitches. These stitches can be removed to increase fluid drainage. Then your physician will apply medications to reduce the risk of scarring.
Some patients will need additional procedures performed if the primary bleb fails due to scarring. The secondary procedure requires the placement of a valve under the conjunctiva with a small tube that is positioned inside the eye to facilitate fluid drainage. This is only performed for those patients with a primary bleb failure, a risk of primary bleb failure, or specific types of glaucoma. Your physician will discuss with you which procedure would be best for your specific diagnosis.
A trabeculectomy is usually done on an outpatient basis with local anesthesia. You will be given a sedative to help you relax. The procedure usually takes about one hour.