Labeled the “sneak thief of sight” because of its silent, gradual progression, Glaucoma is a word that strikes fear in the hearts of many people. It remains one of the leading causes of blindness worldwide, and unfortunately there is no known cure. It is estimated that over 2.2 million Americans have glaucoma, but only half of those are aware they have it.
The good news is that early detection of glaucoma and proper treatment can spare the eyesight of most people with this disease. The diagnosis of glaucoma typically occurs during a comprehensive eye health examination at the optometrist office, rather than by a patient’s complaints about their vision.
Glaucoma is an eye disease that manifests as increased eye pressure damages the optic nerve, a bundle of nerve fibers located at the back of your eye. The optic nerve gathers visual information and sends these cues to the brain to interpret as an image. The liquid that fills the front of your eye is called aqueous, and your eye produces this fluid continuously. As the fluid enters the front chamber of your eye, some of the aqueous must drain out. This requires a constant balance of fluid entering and leaving the eye. If the aqueous fails to drain at the rate needed, this may result in a high eye pressure. Damage to the optic nerve will result in progressive loss of vision.
Vision Loss Progression
Vision damage from glaucoma occurs in a slow, tunnel-vision type pattern. As the outer-most peripheral vision gradually declines, it is rarely noticed by the individual until the loss is profound. The visual fields of our two eyes overlap, so if one eye has a deficiency in a particular area, the other eye usually picks up that area, making the brain still perceive vision in that area. Unless the person covers each eye alternately to test the field of vision of each eye, which most people don’t routinely do, it is common to be unaware of significant visual field loss.
Primary risk factors include African American or Hispanic descent, age of sixty years older, family medical history of glaucoma, history of steroid use, ocular trauma, high myopia, diabetes, or hypertension. Other risks include high eye pressure, thin corneas, history of eye injury (especially blunt trauma), and suspicious optic nerve (larger nerve center than normal).
Glaucoma is largely symptom-less, at least until the very advanced stages. However, if the pressure inside the eye is significantly elevated, you may perceive halos around lights. With substantial vision damage, there may be peripheral vision problems or tunnel vision. Individuals suffering with peripheral vision loss sometimes bump into the wall as they go around corners or complain that they don’t notice cars approaching from the side and rear of their car while driving. Except in the rarest types of glaucoma, there usually is no pain associated with this condition.
No single test allows doctors to arrive at the diagnosis of glaucoma. Multiple complex factors are considered, and the degree each risk factor plays in glaucoma is determined on an individual basis. Findings that include substantial vision loss are “cut and dried” and glaucoma treatment is commenced immediately. However, the most challenging clinical decisions are made when a patient has little or no vision loss but presents with all of the hallmark risk factors and damage may be imminent. Doctors use their knowledge and experience and the clinical findings to determine the diagnosis.
The doctors at Primary Eyecare utilize the latest technologies in the testing and diagnosis of glaucoma patients, including access to multi-dimensional digital imagery of the retina and optic nerve itself within your eyes.
Once the decision to treat glaucoma is made, a number of tools are available to control the disease. Prescription eyedrops are the primary way glaucoma is managed. Intraocular pressure–reducing medications slow down or stop optic nerve damage that leads to vision loss. These medications won’t reverse any vision loss that has already occurred, but they may prevent further loss. There are dozens of prescription eyedrops available, and they each work through different means to achieve the same outcome. Some work to slow down the eye’s ability to produce fluid, and others work by increasing the rate of fluid drainage out of the eye (several prescriptions combine two drugs that use both methods).
Given the common fear about getting glaucoma, and the significant quality-of-life issue that vision loss would entail, the best advice is to make sure that you have an eye examination every year or two at minimum, even if you have no eye problems or don’t wear glasses. A comprehensive ocular exam will spend as much time assessing the overall health of the eye as it does vision. Early detection of glaucoma is essential for preservation of eyesight, and regular eye examinations will allow this terrible eye disease to be stopped in its tracks before it can do serious damage.
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