Glaucoma is the second leading cause of blindness in the world. In the United States, over 3 million are affected by the disease, while only 50% are aware of the diagnosis. Glaucoma accounts for blindness in 120,000 Americans.
It is a complicated disease in which damage to the optic nerve leads to progressive, irreversible vision loss. The optic nerve is made up of greater than 1 million nerve fibers and is similar to a cable made up of wires. Light is transmitted into the eye, onto the retina and changed into electrical signals. The optic nerve sends these signals from the retina to the brain where they are processed into images.
Glaucoma is often associated with elevated eye pressure. Eye pressure, referred to as intraocular pressure (IOP), is determined by the balance of formation and drainage of a fluid that fills the front of the eye called aqueous. Elevated IOP is often the result of blockage or a decrease in drainage from the eye, causing aqueous to build up. Fluid pressure builds up over time and leads to damage to the optic nerve fibers.
Other risk factors for glaucoma include the family history of glaucoma, age greater than 60, increased far or nearsightedness, and history of trauma/surgery/long term steroid use. Also, race is a significant risk factor, as blacks are at 4-6x greater risk, while Hispanics and Asians also have been identified as higher risk.
Also known as the “silent thief,” there are typically no early warning signs or painful symptoms related to glaucoma. This disease causes the slow loss of peripheral vision which may result in “tunnel vision” or complete blindness if left untreated.
Because of the progressive and irreversible nature of the disease, early diagnosis and treatment are key. The American Academy of Ophthalmology (AAO) recommends a baseline comprehensive eye exam at the age of 40, followed by eye exams every 2 years until the age of 65 when annual exams are then recommended. This comprehensive eye exam includes visual acuity testing, intraocular pressure measurement, and dilation. Those identified as higher risk based on their findings may be subject to peripheral vision testing (Visual field), optic nerve imaging, and corneal thickness measurements.
Treatment for glaucoma is aimed at reducing intraocular pressure (IOP). Until recently, the three mainstays of therapy have included medications, laser therapy, and surgery. More recently, treatment for earlier stages of glaucoma may be achieved during cataract surgery with micro-invasive techniques that can be implemented during routine cataract procedures.