Glaucoma is a complicated disease in which damage to the optic nerve leads to progressive, irreversible vision loss. Glaucoma is the second leading cause of blindness.
In the United States, approximately 2.2 million people age forty and older have glaucoma, and of these as many as 120,000 are legally blind from glaucoma.
In most types of glaucoma, the drainage system becomes clogged so that the intraocular fluids cannot drain. This aqueous is the clear watery fluid that is continually produced inside the eye. It is different from your tears. Tears are produced by glands outside of the eye and moisten the outer surface of the eyeball. As the fluid builds up, it causes a pressure to build up within the eye. You have millions of nerve fibers that run from your retina to the optic nerve. As the fluid pressure within your eye increases, it damages the sensitive nerve fiber layers and they begin to die. As they die, the disc begins to hollow and pushes the optic nerve into a cupped or curved shape. If the pressure remains too high for too long, it can result in damage of the optic nerve and eventually result in vision loss.
Vision experts believe that half of those affected by glaucoma may not know it since there are usually no symptoms in its early stages. By the time an individual notices something is wrong, the disease has already caused severe damage. Vision loss to glaucoma cannot be reversed. Visual loss begins with peripheral or side vision. You may compensate for this unconsciously by turning your head to the side and may not notice anything until significant vision is lost. Usually no pain is associated with increased eye pressure in open angle glaucoma, which is the most common form of glaucoma. Therefore, early detection and treatment by your ophthalmologist are the keys to preventing optic nerve damage and blindness from glaucoma, along with regular eye exams. Other signs and symptoms are inability to adjust your eyes in a darkened room and rainbow colored rings or halos around the lights.
1. Visual acuity
2. Visual fields – tests the peripheral vision of each eye.
3. Pupil dilation – allows for a better view of your optic nerve to evaluate whether or not there is any optic nerve damage
5. Tonometry – measures your intraocular pressure
6. Gonioscopy – direction of the drainage angle of your eye
7. Corneal thickness
Some other tests may be necessary, such as photography of the optic nerve or other computerized imaging for certain patients that manifest risk factors. These tests may need to be repeated on a regular basis to manage your progression of the disease.
Everyone is at risk for glaucoma; however, certain groups are at higher risk than others. Risk factors include age, family history of glaucoma, African or Hispanic ancestry, elevated eye pressure, farsighted or nearsighted, past ocular trauma, thinner central corneal thickness, systemic health problems, including diabetes, migraine headaches, poor circulation and steroid users. Your ophthalmologist will review all of these factors before deciding whether you need treatment for glaucoma or if you should be monitored as a glaucoma suspect.
Glaucoma is not curable and vision loss cannot be regained. With medication and/or surgery it is possible to halt further loss of vision. Glaucoma is a chronic condition, and as in hypertension and diabetes, it must be monitored for life. Each patient should be evaluated individually based on his/her past medical history and current medication regime. The appropriate treatment will be chosen for the patient’s glaucoma. Our goal in treatment for glaucoma is to achieve the target pressure with as few medications as possible while minimizing systemic and ocular side effects. It is recommended never to change or stop taking your medication without consulting your ophthalmologist. If you are about to run out of your medication, ask for the prescription to be refilled. Some of the side effects caused by glaucoma medication are stinging or redness of the eye, change in pulse, heartbeat or breathing, tingling of fingers or toes, headaches, mood changes, loss of appetite, change in eye color, change in energy level and dry mouth. Most side effects are not serious and disappear after awhile.
Laser surgery treatment may be recommended for different types of glaucoma. In open angle glaucoma, the drain itself is treated with a procedure called Trabeculoplasty to help control eye pressure. Selective Laser Trabeculoplasty (SLT) is a new procedure performed to lower intraocular pressure (IOP). Canaloplasty is another option your surgeon may recommend. In closed angle glaucoma, the laser creates a hole in the iris (Iridotomy) to improve the flow of aqueous fluid to the drain. If the pressure remains uncontrolled, surgery is recommended by your ophthalmologist in order to prevent further damage to the optic nerve. Usually those procedures are an outpatient procedure.
SLT or Selective Laser Trabeculoplasty
LPI or Laser peripheral iridotomy
The best defense against glaucoma is complete eye exams on a regular basis and compliance with the appropriate medications. Early detection and treatment are imperative for preservation of vision.