Glaucoma
Glaucoma is a disease of the optic nerve, the part of the eye that carries images from the eye to the brain. Glaucoma damages nerve fibers, which can cause blind spots in vision and vision loss.
Early treatment and regular eye exams can often prevent further loss of sight due to glaucoma.
Risk factors include elevated pressure in the eye, family history of glaucoma, Asian ethnicity, advanced age, or certain optic nerve conditions.
Risk factors include elevated pressure in the eye, family history of glaucoma, Asian ethnicity, advanced age, or certain optic nerve conditions. The most common form is primary open–angle glaucoma. The aqueous fluid normally circulates from the back portion of the eye to the front, where it drains out though small holes. In primary open–angle glaucoma, the drainage is partially blocked. This causes the pressure inside the eye to increase, which can damage the optic nerve and lead to vision loss. Most people who develop primary open–angle glaucoma do not notice symptoms until their central vision becomes impaired.
In angle–closure glaucoma, the iris may press against and completely close off the drainage angle, abruptly blocking the flow of aqueous fluid and leading to increased eye pressure, and eventual optic nerve damage, if not treated.
In acute closed–angle glaucoma there is a sudden increase in eye pressure due to the buildup of the aqueous fluid. This condition is considered an emergency because optic nerve damage and vision loss can occur within hours of the problem. Symptoms can include nausea, headache, vomiting, seeing haloes around light, and severe eye pain.
Symptoms
Typically, loss of vision due to glaucoma starts with areas of vision loss in the visual field. Because the side vision is primarily affected, vision loss may not be noticed in day–to–day activities until significant damage, including central vision loss has occurred. Annual glaucoma exams are critical for people 65 years old or older to measure intraocular pressure, drainage of fluids, optic nerve damage, and peripheral vision (right: normal vision on left vs. vision with glaucoma on right).
Treatment
As a rule, damage caused by glaucoma cannot be reversed. Eye drops, surgery, and oral medications may be prescribed to treat glaucoma. To help prevent or reduce progression, surgery may be necessary to control elevated intraocular–pressure (IOP). Glaucoma can continue to progress and adjustment to treatment may be necessary from time to time.