Doctor's Notes on Adult Glaucoma Suspect
Glaucoma is a condition in which high pressure inside the eye damages the optic nerve and can result in permanent vision loss. Intraocular pressure (IOP), or elevated pressure inside the eye, is one of the main risk factors for glaucoma. Glaucoma suspect is an adult with one or more risk factors that may lead to glaucoma, including increasing IOP, but they do not yet have optic nerve damage or vision loss due to glaucoma. Regular eye examinations with an ophthalmologist are important to identify and treat people who are glaucoma suspect. Monitoring for the earliest signs of glaucomatous damage can often help preserve visual function.
People who are glaucoma suspect do not usually have any symptoms of glaucoma. Symptoms of possible angle-closure glaucoma may include intermittent headaches, seeing haloes, or blurred vision. Once vision loss is apparent, significant amounts of optic nerve damage have already occurred. The optic nerve damage and vision loss are permanent.
Adult Glaucoma Suspect Symptoms
People who are glaucoma suspect do not usually experience any symptoms. Those with possible angle-closure glaucoma may experience intermittent headaches, see haloes, or have blurred vision. By the time people with glaucoma would notice vision loss, significant amounts of optic nerve damage and vision loss have already occurred. The optic nerve damage and vision loss are permanent.
Adult Glaucoma Suspect Causes
The mechanisms that cause glaucoma are not fully understood. In most cases, a painless elevation of IOP occurs, which can lead to progressive vision loss and optic nerve damage.
High pressure inside the eye is caused by an imbalance in the production and drainage of fluid in the eye (called aqueous humor). The channels (called trabecular meshwork) that normally drain the fluid from inside the eye do not function properly. More fluid is continually being produced but cannot be drained because of the improperly functioning drainage channels. This results in an increased amount of fluid inside the eye, thus raising the pressure.
Another way to think of high pressure inside the eye is to imagine a water balloon. The more water that is put into the balloon, the higher the pressure inside the balloon. The same situation exists with too much fluid inside the eye—the more fluid, the higher the pressure. Also, just like a water balloon can burst if too much water is put into it, the optic nerve in the eye can be damaged by too high of a pressure. See Media files 1-2.
Certain risk factors are associated with the development of glaucomatous damage. The greater the number and the degree of risk factors, the greater the risk of developing glaucoma over time.
The following historical and demographic factors have shown a high association for the disease:
- Family history is a definite risk factor.
- A significant percentage of people with glaucoma have a positive family history.
- Family history of glaucoma in a sibling is the greatest risk factor, followed by glaucoma in a parent.
- Increasing age
- Race, particularly African American
In addition to elevated IOP, the following eye conditions have been implicated as risk factors for developing glaucoma:
- Glaucoma already present in one eye
- Congenital abnormalities (abnormalities present from birth): The underlying cause of glaucoma may be from congenital variations in the eye, especially in the appearance of the optic nerve.
- Onetime trauma to the eye or prior eye surgery: This may indicate that the optic nerve damage is not progressive but may have been because of an isolated incident. The key is whether any progression occurs.
- Suspicious looking optic nerve or an optic nerve defect
- Susceptibility of the optic nerve to damage varies from individual to individual. Along with other risk factors, the likelihood of optic nerve damage also depends on the level of IOP.
- Problems with blood supply to the optic nerve may play a role. This is especially important in individuals with normal-tension glaucoma who have progressive disease despite IOP of less than 21 mm Hg. See Normal-Tension Glaucoma.
- Narrow angles
- Nearsightedness (myopia)
- Pseudoexfoliation: Flakes of material are produced inside the eye that obstruct the trabecular meshwork, causing a rise in IOP.
- Pigment dispersion
- The iris releases pigment inside the eye that obstructs the trabecular meshwork, causing a rise in IOP.
- With pigment dispersion, the risk of glaucoma increases by 25-50%.
- History of uveitis or other inflammatory eye disease: Uveitis is an inflammation of the uvea, that is, the iris, the ciliary body, and the choroid.
- Central retinal vein occlusion: Some people’s first sign of disease from elevated IOP can be sudden vision loss due to the vein in the central part of the retina becoming blocked, called a central retinal vein occlusion.
The following medical conditions have been associated as risk factors for developing glaucoma:
- Current or past use of topical steroids
- Topical steroids may elevate IOP in certain people.
- Optic nerve damage may occur from a previous episode of increased IOP associated with topical steroid use. The elevation of IOP is usually seen within a few weeks of starting topical steroids.
- History of vasospastic disorders (spasms or constrictions of the blood vessels): Migraine headaches occur more often in people with normal-tension glaucoma.
- Heart disease, particularly in those with normal-tension glaucoma
Just like every other part of the body, eyes age and do not work as well as we get older. Poor diet, excess sun exposure, toxins, infections, and physical and emotional stressors cause wear and tear on the body, including our eyes. This wear and tear produces free radicals, unstable molecules that harm us at the cellular level. The eyes are prone to damage by free radicals. This damage may result in you having vision problems or suffering from age-related macular degeneration or other eye disorders, but you can help protect your eyes by making healthy food choices.
Antioxidants like vitamin C, vitamin E, vitamin A, beta-carotene, zinc, lutein, zeaxanthin, and omega-3 fatty acids protect against free radical damage that can harm your eyes. You can find these nutrients by eating colorful fruits and vegetables that will protect your eyes and boost your overall health. We’ll take a look at these on the following slides.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.