Once you notice vision loss, the damage is permanent.1 Because high IOP is a risk factor for glaucoma, your doctor may prescribe medicine that can help lower it.2 That’s why early detection is critical. Below are several of the most common tests eye care professionals may use to diagnose glaucoma:3
Ophthalmoscopy, is a test where the doctor looks at the inside of the eye and retina to see if there are any signs of damage to your optic nerve.
Tonometry measures the pressure within your eye by applying pressure to the cornea with a tiny device or a puff of air. Normal intraocular pressure (IOP) is generally between 12-22 mm Hg (millimeters of mercury). Intraocular pressure (IOP) over 22 mm Hg is considered higher than normal, but no one number applies to everyone.4 Normal pressure for one person could be high for another. The amount of pressure the optic nerve can take without being damaged is what counts.5
Pachymetry measures the thickness of your cornea, which may influence eye pressure readings.6 Research suggests patients with thin corneas are three times more likely to develop glaucoma.7
Gonioscopy helps determine if the drainage channel or angle in the eye is open, narrow or otherwise closed.
Perimetry is a visual field test that will help the doctor determine whether your vision has been affected by glaucoma.8 This is important because vision lost from glaucoma tends to occur on the sides first.9
A Slit Lamp Examination uses a specialized instrument called a biomicroscope to provide a magnified view of your eyes’ anatomy. In addition to other parts of your eye, your doctor can view the optic nerve and area where fluid drains out of the eye to help detect any problems.10,11
A Funduscopic Examination is performed by your doctor using an instrument called a binocular indirect ophthalmoscope. After dilating your eyes, your doctor can use its powerful lens to focus light into your eye, providing a larger field of view for diagnosing your internal eye health.12
Optical Coherence Tomography (OCT) can scan your eye and provide your doctor with a cross-sectional view of your retina. Among other things, it is often used to evaluate disorders of the optic nerve.13
1. National Institutes of Health, Medline Plus. Glaucoma. http://www.nlm.nih.gov/medlineplus/ency/article/001620.htm. Accessed February 11, 2013.
2. National Eye Institute. Facts About Glaucoma. http://www.nei.nih.gov/health/glaucoma/glaucoma_facts.asp. Accessed February 11, 2013.
3. Glaucoma Research Foundation. Five Common Glaucoma Tests. http://www.glaucoma.org/glaucoma/diagnostic-tests.php. Accessed February 11, 2013.
4. Glaucoma Research Foundation. High Eye Pressure and Glaucoma. http://www.glaucoma.org/gleams/high-eye-pressure-and-glaucoma.php. Accessed February 11, 2013.
5. National Eye Institute. Facts About Glaucoma. http://www.nei.nih.gov/health/glaucoma/glaucoma_facts.asp. Accessed February 11, 2013.
6. Glaucoma Research Foundation. Five Common Glaucoma Tests. http://www.glaucoma.org/glaucoma/diagnostic-tests.php. Accessed February 11, 2013.
7. Lighthouse International. Reducing Risk of Glaucoma. http://www.lighthouse.org/eye-health/prevention/reducing-risk-of-glaucoma/. Accessed March 12, 2013.
8. Glaucoma Research Foundation. Five Common Glaucoma Tests. http://www.glaucoma.org/glaucoma/diagnostic-tests.php. Accessed February 11, 2013.
9. Glaucoma Research Foundation. Glaucoma Facts and Stats. http://www.glaucoma.org/glaucoma/glaucoma-facts-and-stats.php. Accessed February 11, 2013.
10. WebMD, Slit Lamp Examination, http://www.webmd.com/eye-health/slit-lamp-examination. Accessed March 12, 2013.
11. About Vision, Slit Lamp Examination, http://vision.about.com/od/eyeexamination1/qt/Slit_Lamp_Exam.htm. Accessed March 12, 2013.
12. About Vision, What Happens During an Eye Exam?, http://vision.about.com/od/eyeexaminations/f/Eye_Tests.htm. Accessed March 12, 2013.
13. American Academy of Ophthalmology, eyeSmart, What Conditions Can OCT Help to Diagnose? http://www.geteyesmart.org/eyesmart/diseases/what-does-optical-coherence-tomography-help-diagnose.cfm. Accessed March 12, 2013.