Glaucoma causes progressive damage to your optic nerve, resulting in vision loss and blindness in advanced stages. The eye disorder is associated with increased fluid pressure inside the eyes, which affects nerve tissues that transmit visual signals to your brain. If you have vision problems or eye health issues, your eye doctor can perform a comprehensive exam, including glaucoma tests. Here’s how an optometrist tests for glaucoma:
Intraocular Pressure Measurement
Since glaucoma is linked to pressure buildup in your eyes, the first diagnostic procedure involves testing eye pressure. Also known as tonometry, intraocular pressure measurement tests use a small device to gently press on your cornea. This test provides a more accurate diagnosis by probing the eye to assess pressure levels. The optometrist applies numbing drops to reduce discomfort and allow uninterrupted evaluation. Eye doctors also perform non-contact tonometry, which uses a puff of air to flatten your cornea. Tonometry tests help identify elevated intraocular pressure, the leading risk factor for glaucoma.
A thick or thin cornea can affect intraocular pressure readings, resulting in misinterpretation and misdiagnosis. Corneal thickness measurement determines the thickness of your cornea to help doctors make proper pressure readings. The exam involves gently probing the cornea to measure its thickness. A normal corneal thickness reading helps confirm glaucoma if other tests indicate higher pressure readings. A thicker reading warrants further diagnosis to support the high intraocular pressure reading.
Optic Nerve Examination
An optic nerve examination or ophthalmoscopy is a glaucoma evaluation involving a special lens and light. The test allows eye doctors to examine your pupil and the optic nerve that carries images to your brain. Doctors can see cupping, changes in the optic disc color or shape, and other signs of damage caused by glaucoma. Cupping occurs when a depression forms in the center of the optic nerve.
The examination involves using drops to dilate your pupils and a magnifying lens and light to inspect the eye. Glaucoma damages your optic nerves, making ophthalmoscopy an effective test for diagnosing the condition. The doctor can also take images of the optic nerve and monitor for changes over time.
Visual Field Testing
Perimetry or visual field testing helps eye doctors assess your peripheral vision. The test maps your side vision, allowing the doctor to identify vision loss patterns linked to glaucoma. Perimetry involves sitting at a machine and looking ahead as light flashes in different areas of your visual field. The doctor assesses your response to light flashes to map out your visual field and detect changes. Glaucoma causes progressive vision loss, and perimetry maps out your visual field, indicating changes to your peripheral vision.
Drainage Angle Assessment
Also known as gonioscopy, drainage angle assessment is a glaucoma evaluation that reviews where fluid drains out of your eye. A special contact lens featuring mirrors is placed on your eye to view the drainage angle and check for blockage. If the drainage angle is blocked, it can cause fluid and pressure buildup, leading to optic nerve damage and glaucoma.
Optical Coherence Tomography
Optical coherence tomography is an imaging test that uses light rays to measure the thickness of the retinal nerve fiber layer. The test provides detailed cross-sectional images of your retina and optic nerve, helping an optometrist detect early damage caused by glaucoma. Optical coherence tomography is non-invasive and is often used to monitor glaucoma development over time. The examination involves a machine that scans the back of your eye to produce images that doctors interpret.
Speak to an Optometrist Today
Testing for glaucoma allows you to detect early signs and begin interventions to prevent further damage or slow progression. These tests require experienced doctors and specialized equipment. Contact an optometrist today to learn more about glaucoma diagnoses and other eye health conditions.
