Glaucoma Tests
Reviewed
Also called: Tonometry, Ophthalmoscopy, Visual Field Test, Perimetry, Gonioscopy, Pachymetry
Glaucoma tests are eye tests that help diagnose glaucoma. Glaucoma is a group of eye diseases that can damage a nerve in the back of your eye called the optic nerve.
Specimen: Not applicable
Urgent safety information
Acute closed-angle glaucoma is a medical emergency. No fluid can drain out of your eye, so eye pressure increases suddenly. This causes eye pain, blurry vision, and other symptoms. Without prompt treatment, it can cause blindness in a few days.
Why this test may be ordered
- To screen for glaucoma before symptoms appear
- To diagnose glaucoma if you have symptoms or risk factors
- To monitor glaucoma and check if treatment is working
Preparation and collection
If you wear glasses or contact lenses, bring them with you. Bring sunglasses to wear after your exam in case your eyes are sensitive to light. Also, plan to have someone take you home because your vision may be blurry.
Glaucoma tests are done as part of a comprehensive (complete) eye exam. A complete eye exam checks both your vision and your eye health. If you're unsure which type of eye specialist should check you for glaucoma, talk with your provider.
There is no risk to having glaucoma testing. Some of the tests may feel a bit uncomfortable. If your eyes were dilated, you may have blurry vision and be light sensitivity for a few hours.
Understanding results
If your test results aren't normal, you may have glaucoma or a high risk for developing glaucoma.
- High eye pressure on an air-puff screening test: If the results show that your eye pressure is high, your provider will do other eye-pressure tests to get a more accurate measurement. Limitation: Its thickness can affect the results of your eye-pressure measurements. Next step: If your eye pressure is high, a pachymetry test gives your eye care specialist more information about how high it may be.
- Test results not normal: If your test results aren't normal, you may have glaucoma or a high risk for developing glaucoma. Limitation: Treatment won't cure the disease or restore any vision you have already lost. But it can prevent more vision loss. Next step: If an optometrist examined your eyes, you may be referred to an ophthalmologist for more testing and/or treatment.
- Screening tests like the air-puff test may be less accurate than other methods and can give false-positive or false-negative results.
- Normal test results do not completely rule out glaucoma, especially normal-tension glaucoma.
- Abnormal test results do not always mean you have glaucoma; other eye conditions can cause similar findings.
- After dilation, you may have blurry vision and light sensitivity for a few hours, which can affect daily activities.
What to do next
Ask your eye care specialist to explain your test results and be sure to find out how often you should have your eyes checked.
- What is my risk for developing glaucoma based on my age, race, and family history?
- How often should I have glaucoma tests?
- What do my specific test results mean for my eye health?
- What are the treatment options if I am diagnosed with glaucoma?
- What symptoms should I watch for that would require immediate medical attention?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.