A: Glaucoma<\/a> is a progressive ocular disease that causes permanent vision loss, as a result of damage to the optic nerve that carries visual signals between the eye and brain.<\/p>\n A: Glaucoma has been nicknamed the silent thief of sight because it often causes permanent vision loss before the disease is even detected. In its early stages, glaucoma does not typically present with any symptoms that would send you to your eye doctor with complaints of vision changes. Therefore, by the time you see your eye doctor, a large amount of vision loss has already occurred.<\/p>\n A: Glaucoma is caused by high levels of pressure within the eye.<\/a> This intraocular pressure (IOP) presses on the optic nerve, causing damage, and eventually leading to permanent vision loss.<\/p>\n A: Pressure builds within the eye as a result of a problem in the eye\u2019s drainage system. In a healthy eye, the aqueous humor, or fluid, is produced within the eye\u2014 and as it drains out of the eye through the anterior angle, new fluid is produced. This process repeats itself continuously, and if effective, maintains a normal level of eye pressure.<\/p>\n When a problem occurs within the drainage system, and the eye\u2019s natural drain becomes clogged, the fluid builds up in the eye, and consequently causes a buildup of pressure within the eye.<\/p>\n An easier way to understand how eye pressure increases, is imagining the sink in your kitchen. When the faucet is turned on, the water flows into the basin of the sink and continues down the drain pipe. When there is a blockage in the drain pipe, the water continues to flow into the pipe, causing increased pressure in the pipe.<\/p>\n Just as constant high pressure within the drain pipe will cause damage over time and may lead to a burst pipe, constant high pressure in the eye will eventually lead to optic nerve damage, and consequently vision loss.<\/p>\n A: Peripheral vision is affected first, and if not effectively controlled at this point, can result in tunnel vision. As the disease progresses, central vision is affected next, leaving the person with partial, or complete permanent <\/i>vision loss.<\/p>\n A: If glaucoma is not effectively controlled at an early stage, the disease can cause severe peripheral vision loss\u2014 resulting in a condition called \u2018tunnel vision\u2019. Tunnel vision blocks your \u2018side vision\u2019, and limits your field of vision to strictly seeing images in your central vision, or straight ahead.<\/p>\n A: There are four primary types of glaucoma:<\/p>\n 1. Chronic (open angle) glaucoma<\/a><\/b> is the most common form, caused by IOP build-up over time,<\/i> typically as a result of aging.\u00a0Open angle glaucoma affects approximately 2.7 million Americans, above the age of 40.<\/p>\n 2. Acute (angle closure) glaucoma<\/a><\/b> is a rare form that requires immediate medical attention. It develops as a result of sudden <\/i>pressure build-up. Symptoms include blurred vision, seeing halos around lights, eye pain, headaches, nausea and vomiting.\u00a0 Acute angle closure glaucoma affects about 1 in 1,000 people.<\/p>\n 3. Secondary glaucoma<\/b> can develop from complications of medical conditions such as, diabetes and hypertension, other ocular conditions, side effects of medications, or trauma to the eye.\u00a0Secondary glaucoma accounts for 10% of all glaucoma cases.<\/p>\n 4. Normal tension glaucoma<\/a><\/b> develops when the optic nerve is damaged, without a presence of high IOP. The cause of this type of glaucoma is still unknown.\u00a0Normal tension glaucoma accounts for approximately 30-40% of all patients diagnosed with glaucoma.<\/p>\n A: Glaucoma is diagnosed during a comprehensive eye exam, using specific diagnostic tools and assessments:<\/p>\n Tonometry<\/b> calculates your intraocular pressure (IOP) based on your eye\u2019s response to a puff of air.<\/p>\n Tonometer or tonopen <\/b>is a tool used to obtain another measure of your IOP. During this test, your eyes will be numbed so that your doctor can gently touch the surface of your eye with either a tonometer or tonopen.<\/p>\n An optical coherence tomography (OCT) scan<\/b> is a non-invasive, diagnostic tool that uses a laser to provide color-coded, cross sectional images of the retina and optic nerve.<\/p>\n A visual field test<\/b> produces a computerized map of your visual field and measures the range of your peripheral vision.<\/p>\n Optic disc examination<\/b> involves a thorough evaluation of the surface of the optic nerves, to examine the quality of the margin, or neuroretinal rim, and optic disc cup.<\/p>\n This examination can be performed with direct ophthalmoscopy, slit lamp, optic disc photography, or with digital imaging devices.<\/p>\n Examination of anterior angle (<\/b>gonioscopy)<\/b> enables a thorough evaluation of the anterior angle, the internal drainage system of the eye, located between the iris and cornea.<\/p>\n Through this test, your eye doctor will be able to determine if the angle is open or closed, and detect the presence of abnormal blood vessels, adhesions (synechiae), or damage from previous eye trauma.<\/p>\n To enable a clear view of the angle and its drainage system, your eyes will be numbed, and a special contact lens prism will be placed on the surface of your eye. This test is relatively quick, and does not cause any pain, though you may feel some pressure from the contact lens.<\/p>\n If you suspect you have any eye condition, contact an eye doctor<\/a>\u00a0near you, who can diagnose and treat the condition.<\/strong><\/p>\n SEE RELATED:<\/strong> Normal Tension Glaucoma<\/a><\/p>\n\n\tQ2: How common is glaucoma?<\/b><\/h2>\n
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Q3: Why is glaucoma called \u2018The Silent Thief of Sight\u2019?<\/b><\/h2>\n
Q4: How does glaucoma cause vision loss?<\/b><\/h2>\n
Q5: What causes high eye pressure?<\/b><\/h2>\n
Q6: Will glaucoma affect <\/b>all <\/i><\/b>of my vision?<\/b><\/h2>\n
Q7: What is \u2018tunnel vision\u2019?<\/b><\/h2>\n
\u00a0Q8: Is there only one type of glaucoma?<\/b><\/h2>\n
Q9: How is glaucoma diagnosed?<\/b><\/h2>\n