Glaucoma: Causes, Symptoms, and Treatments

Glaucoma is a collective name of a group of eye conditions which develop when fluid pressure builds up in the eye (referred to as intraocular pressure), damaging the optic nerve. As the optic nerve is responsible for transmitting images from eyesight to the brain, just as bundled wires communicate websites over the Internet to your computer, glaucoma inevitably diminishes sight and causes blindness if left untreated. It quietly affects the eye even before symptoms may be acknowledged by the patient, as sight loss is so gradual and often accepted as a simple result of aging. Glaucoma is the second leading cause of permanent, complete blindness in adults and children and it is the pervasive and stealthy advancement of this condition that has caused it to become known as "The Silent Thief of Sight."

Types of Glaucoma

There are several types of Glaucoma, some of which are inherited:

Primary Open Angle Glaucoma (POAG) is the most common form resulting from intraocular pressure caused by clogged drainage canals in the eye. About 3 million U.S. adults are affected by this version of the eye condition, which involves clogging deep in the eye drainage canals, not at the surface where such a condition might be more easily detected. Although POAG can be diagnosed and treated through medication when found by an eye care practitioner, most patients do not detect the sinister and gradual changes until vision is significantly lost.

Angle Closure Glaucoma (ACG) is a less-frequent diagnosis versus the more common POAG. ACG is sometimes called Narrow Angle or Acute Glaucoma. It affects the eye much more rapidly than POAG as the root cause (eye pressure increase) develops faster through clogging or covering over of the drainage canals at the exit point (as compared to POAG's clogging deeper under the surface). When ACG occurs, the iris is affected by becoming more narrow and bunched up than it should be over the canals. When transitioning from varying light levels, such as when a light switch is turned on in a dark room, the pupil is unable to adjust as it should in reaction to the environment and because of the condition. The resulting symptoms are bothersome headaches, auras and rainbows around lights, blurred vision, aching eyes, and nausea. Surgery can correct angle closure glaucoma for at least the short term, with a good long-term prognosis when coupled with frequent eye exams.

Normal Tension Glaucoma (NTG) is when glaucoma presents without increased internal eye pressure. NTG is often inherited and occurs more frequently in people of Japanese descent or in those with a history of systemic heart disease. Though doctors don't know what causes NTG, they detect it through an eye exam and can treat it with laser surgery, filtering surgery, or medicines that lower eye pressure, such as specialized eye drops.

Secondary Glaucomas are caused by eye injury, advanced diabetes, inflammation, serious cataracts, tumors, or even by steroids and other drugs. Secondary glaucomas are also either angle closure or open angle. Secondary glaucomas include: pseudoexfoliative, pigmentary, traumatic, and neovascular glaucomas, as well as irido corneal endothelial syndrome (ICE). Each of the secondary glaucomas have different causes, although most are treatable through medications or surgery. Unfortunately, neovascular glaucoma is not easily treated.

Glaucoma in Children

Glaucomas that occur in children need to be detected and treated early to ensure sight is not lost. Congenital Glaucoma is present at birth. Infantile Glaucoma is found up to age thirty-six months and Juvenile Glaucoma is found from age three years to early adulthood. Children are also affected by secondary glaucomas.

Conclusion

Regardless of the type of glaucoma diagnosed, early detection, medical attention, and treatment through the appropriate means (medications or surgery) and ongoing eye exams are critical. Loss of eyesight is not inevitable in most patients, if treated.

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