What is Glaucoma?
Glaucoma is a disease that may be associated with elevated intraocular pressure that can cause progressive loss or damage to the optic nerve with eventual blindness. Light enters your eye and travels to the retina, the inner layer of the eye. The retina sends signals to the optic nerve, which then transmits the signals to your brain.
In the normal eye, a fluid called aqueous humor is formed in the front of the eye, and then drains out through tiny drains called the trabecular meshwork. There is a pressure inside the eye that is required for health and falls within a certain range, usually 10-21 mmHg.
With glaucoma, the aqueous humor does not drain properly, leading to increased pressure in the eye. The fluid build up can be gradual, with slow progression of the disease and no early symptoms. Glaucoma is a silent thief that steals your sight very slowly.
Patients who have open angle glaucoma may not experience symptoms in the early stages. As the glaucoma progresses with damage to the optic nerve, you may notice blind spots in your side (peripheral) vision. Patients who are risk for narrow angle glaucoma, because the drainage angle gets blocked, may not have any symptoms until they get an attack. Some early symptoms of early narrow (acute) glaucoma include halos, headaches, eye pain, redness, or blurred vision. During an attack of acute glaucoma, symptoms include eye redness, blurry vision, headache, nausea and vomiting, halos around lights, and intense eye or brow pain.
In some patients with normal tension glaucoma, the pressure in the eye is in the normal range, but they develop symptoms of glaucoma such as trouble seeing in there side (peripheral) vision. In other patients (almost 8%), their pressure can be higher than normal, but not experience any symptoms of glaucoma. These patients are called “glaucoma suspects”.
Types of Glaucoma
There are several different types of glaucoma, which can cause increased intraocular pressure as a result of different factors, and may include:
Primary Open Angle Glaucoma: This is the most common form of glaucoma (60-70%), which occurs in about 2-5% of the population over 40 years, increasing with age.Open angle glaucoma occurs when the fluid inside your eye fails to drain normally from the eye, with a pressure build up. This pressure build up causes damage to the optic nerve. The pressure varies throughout the day, so that 50% of patients who have glaucoma have normal pressures on exam, but sometimes higher at a different time of day. Symptoms are usually not present initially, and slowly progress with damage to the periphery of vision.
Primary Narrow Angle Glaucoma: This occurs when the optic nerve is damaged due to decreased outflow due to mechanical obstruction of the trabecular meshwork.
Low/Normal Tension Glaucoma: This occurs when the optic nerve is damaged but intraocular pressure does not rise. This type of glaucoma is seen in patients with migraines, autoimmune disease, and poor blood flow to the optic nerve, such as from a heart attack or massive hemorrhage.
Ocular Hypertension: This occurs when there is a higher pressure than normal, but no signs of glaucoma, such as trouble seeing in the periphery. These patients are called glaucoma suspects and followed because of the risk of developing glaucoma.
Treatment of Glaucoma
There are several medical and surgical options for the treatment of glaucoma. Please consult your eye doctor for treatment options tailored to your condition and stage of glaucoma.