Glaucoma
Allen D. Beck, MD
Anastasios Costarides, MD, PhD
Annette Giangiacomo, MD
Paul Pruett, MD
Glaucoma is a group of diseases that damage the eye's optic nerve and can result in vision loss and blindness. However, with early detection and treatment, you can often protect your eyes against serious vision loss. The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
A comprehensive eye exam is necessary to diagnose glaucoma. The exam will include: tonometry to measure pressure inside the eye; pachymetry, which measures the corneal thickness, gonioscopy, an assessment of the drain of the eye; a visual field test to determine peripheral vision loss; a dilated eye exam to examines the retina and optic nerve; and possibly special scans or pictures of the optic nerve.
Emory glaucoma specialists are nationally known for developing innovative instruments, surgical techniques and laser procedures to treat glaucoma in both adults and children. Emory has participated in the Advanced Glaucoma Treatment Study (AGIS) and the Ocular Hypertensive Treatment Study (OHTS), sponsored by the National Institutes of Health. Emory glaucoma specialists are also engaged in researching the latest medications available on the market to halt the progression of this blinding disease.
Type of Glaucoma
Primary Open-Angle Glaucoma: The drainage angle is open within the eye, but for unknown reasons, does not allow fluid to drain. One to two percent of Americans have this form; it is the most common form of glaucoma and occurs mainly in those over 40 years old. Medications are usually used to treat this form of glaucoma, much like systemic hypertension. However laser and other surgical treatments are used depending on the severity of the glaucoma.
Normal Tension Glaucoma or Low Tension Glaucoma: Has progressive optic nerve damage and subsequent visual field loss with normal intraocular pressure. The form of glaucoma is treated in similar fashion to primary open-angle glaucoma.
Angle-Closure Glaucoma: Can be inherited and is more common in some Asian populations. Unlike primary open angle glaucoma, angle closure glaucoma is more common in those who are far-sighted (hyperopic). The anterior chamber of the eye is smaller than average, and ultimately causes fluid pressure to build up behind the iris over time, narrowing the angle where the iris and cornea meet. At the most severe, the drainage becomes completely blocked, creating an angle-closure glaucoma attack or acute glaucoma. In this form, the eye pressure increases suddenly within hours and can become painful and cause nausea. The eye becomes red, the cornea can swell and cloud and the patient sees haloes around lights. Vision is blurred. This is an emergency condition. If treatment is not immediate, vision can be permanently lost. Laser treatment can prevent angle closure glaucoma and halt an acute angle-closure attack. Medications and surgery are also used to treat angle closure glaucoma.
Pigmentary Glaucoma: A type of open-angle glaucoma occurring in near-sighted patients in their 20s and 30s. Excessive pigment is present throughout the eye and drainage system. Medications, laser, and surgery can be used to treat the condition.
Exfoliative Glaucoma: Found throughout the world, but more common to those of Scandinavian descent. A whitish material forms in the front part of the eye and can be seen best on the lens of the eye. The whitish material may clog the drain of the eye, leading to higher eye pressure. It is most common in individuals over seventy years of age. Exfoliative glaucoma is usually more difficult to treat with medications than primary open angle glaucoma, although laser and other surgical treatments can be effective.
Traumatic Glaucoma: A blow to the eye, chemical burn or penetrating injury can lead to glaucoma months or years after the injury through damage to the drain of the eye.
Childhood Glaucoma: Usually glaucoma that develops in childhood is due to a birth defect, trauma, or may be associated with ocular surgery. In primary congenital glaucoma, the child’s drainage channels develop abnormally during gestation. The infant usually has characteristic symptoms of tearing and light sensitivity due to swelling in the cornea. This form of childhood glaucoma usually requires surgical treatment.
What are the risk factors for primary open-angle glaucoma?
Although glaucoma is most common in adults over the age of 40, propensity is not determined by age alone. There are inherited and acquired factors. Those at greater risk:
- Have elevated eye pressure
- Have a family history of the disease
- Are African-American
- Are nearsighted
- Are diabetic
- Are hypertensive
Where can I get more information about glaucoma?
American Academy of Ophthalmology:www.geteyesmart.org
American Glaucoma Society:www.glaucomaweb.org
Glaucoma Research Foundation:www.glaucoma.org
National Eye Institute: www.nei.nih.gov
First paragraph on this page courtesy of: National Eye Institute, National Institutes of Health (NEI/NIH).
