Common Tests Used to Diagnose Glaucoma
Glaucoma affects nearly three million Americans. Unfortunately, it is estimated that about half of those affected are unaware they suffer from the condition. Many do not recognize the symptoms of glaucoma, so they fail to seek diagnosis and treatment. Typical glaucoma symptoms include vision loss, tunnel vision, blind spots in the central or peripheral vision, and headaches.
Eye doctors at Monterey County Eye Associates, which serves Monterey, Salinas, and King City, CA, offer glaucoma testing to diagnose this eye disease. Here, our doctors discuss the two primary types of glaucoma and the most common tests used to diagnose glaucoma so we can help patients manage the disease and preserve their vision.
Types of Glaucoma
There are two types of glaucoma: open-angle glaucoma and angle-closure glaucoma. Each type of glaucoma affects the eyes differently and causes its own unique symptoms.
The most common form of glaucoma is open-angle glaucoma. Open-angle glaucoma is caused by a gradual clogging of the eye’s drainage canals. Without proper draining, fluids build up behind the eye and increase intraocular pressure. Symptoms of open-angle glaucoma include blind spots and tunnel vision, which are not always easily recognized.
Angle-closure glaucoma is also caused by blocked drainage canals but it creates a narrow angle between the iris and the cornea. This form of glaucoma causes more obvious symptoms, such as blurry vision, vision loss, nausea, eye pain, and headaches.
Testing for Glaucoma
Anyone experiencing potential glaucoma symptoms should schedule a comprehensive eye exam to discuss their concerns with our eye doctors. In addition, we recommend that individuals with a higher risk of developing glaucoma (individuals aged 60 or older, those with a family history of the condition, individuals with high blood pressure or other medical conditions linked to the disease, etc.) undergo glaucoma testing once a year.
Glaucoma testing is non-invasive, pain-free, and can usually be completed in a couple of hours. The most common tests to diagnose glaucoma include an eye pressure check, visual field testing, gonioscopy, optic nerve photographs, and corneal thickness test.
Eye Pressure Check
Increased eye pressure is the most common indicator of glaucoma, so an eye pressure test is essential to diagnosing the disease. During this test, our doctors numb the eyes with eye drops and then use a tiny instrument to measure intraocular pressure.
Visual Field Test
A visual field test measures a person’s peripheral vision and the sensitivity of various parts of their sight. During the exam, the patient looks straight ahead and signals to our doctors when they see a light or object in their peripheral vision.
Gonioscopy
A gonioscopy measures the angle between the iris and cornea. During the test, the doctor places an exam contact lens on the cornea’s surface. The contact lens provides a visual of the angle and the helps determines if the drainage angle is functioning properly.
Optic Nerve Photographs
To obtain optic nerve photographs, the patient’s eyes are dilated. With the eyes dilated, our doctors use a digital camera and optical coherence tomography technology to create a magnified 3-D image of the optic nerve. The doctors can diagnose glaucoma based on the shape, color, depth, and size of the vessels in the optic nerve.
Corneal Thickness Test
A corneal thickness test uses a small probe to painlessly measure the thickness of the cornea. Thin corneas increase the risk of glaucoma and may contribute to artificially low eye pressure readings. Thick corneas can contribute to artificially high eye pressure readings.
Contact Monterey County Eye Associates
If you are experiencing potential glaucoma symptoms, are at high risk for the disease, or are past due for a comprehensive eye exam, scheduling a glaucoma test may be a good idea. To schedule an exam at Monterey County Eye Associates, contact our practice today.