Glaucoma is a leading cause of blindness especially for older people. It is a disease of the optic nerve. When damage to the optic nerve occurs, Blind spots in the field of vision develop, and usually go undetected until the optic nerve is significantly damaged. Early detection and treatment are the keys to preventing optic nerve damage.
Clear liquid called aqueous humor circulates inside the front portion of the eye and flows out through a drainage system (located in the angle of the anterior chamber). If the drainage angle is blocked or inefficient, the aqueous humor cannot flow out of the eye. Fluid pressure within the eye increases, pushing against the optic nerve and causing damage.
Chronic open-angle glaucoma: This is the most common form of glaucoma. The drainage angle becomes less efficient over time, and pressure within the eye gradually increases, which can damage the optic nerve. Typically, open-angle glaucoma has no symptoms in its early stages, and vision remains normal. As the optic nerve becomes more damaged, blank spots begin to appear in your field of vision.
Closed-angle glaucoma: Some eyes are formed with the iris (the colored part of the eye) too close to the drainage angle. In these eyes, which are often small and farsighted, the iris can block the drainage angle completely. The pressure inside the eye builds rapidly and causes an acute closed-angle attack. Symptoms may include: blurred vision, severe eye pain, headache, rainbow-colored halos around lights, and nausea and vomiting. This is a true eye emergency – call your eye doctor immediately. Unless this type of glaucoma is treated quickly, blindness can result.
The most important risk factors include age, elevated eye pressure, family history of glaucoma, farsightedness or nearsightedness, past eye injuries, thinner central corneal thickness, systemic health problems, including diabetes, migraine headaches, and poor circulation.
Your ophthalmologist will weigh all of these factors before deciding whether you need treatment for glaucoma, or whether you should be monitored closely as a glaucoma suspect.
Regular eye examinations by your ophthalmologist are the best way to detect glaucoma. The only sure way to detect glaucoma is to have a complete eye examination.
During your glaucoma evaluation, your ophthalmologist will: measure your intraocular pressure (tonometry); inspect the drainage angle of your eye (gonioscopy); evaluate whether or not there is any optic nerve damage (ophthalmoscopy); and test the peripheral vision of each eye (visual field testing, or perimetry).
As a rule, damage caused by glaucoma cannot be reversed. Eye drops, laser surgery, and surgery in the operating room are used to help prevent further damage. In some cases, oral medications may also be prescribed. Periodic examinations are very important to prevent vision loss. Because glaucoma can progress without your knowledge, adjustments to your treatment may be necessary from time to time.
Regular medical eye exams help prevent unnecessary vision loss. Recommended intervals for eye exams are:
Ages 20 to 29: Individuals with a family history of glaucoma should have an eye examination every 3 to 5 years. Others should have an eye exam at least once during this period.
Ages 30 to 39: Individuals with a family history of glaucoma should have an eye examination every 2 to 4 years. Others should have an eye exam at least twice during this period.
Ages 40 and older: Every year.