Glaucoma Screening: Eye Pressure Testing
Using Tonometry to test pressure inside the eye will normally be the first step in screening for Glaucoma. Eye pressure is measured in millimeters of mercury (mm Hg), with normal eye pressures ranging from 12-22 mm Hg.
Examples of tonometers include:
- Air Puff (or Non-Contact) Tonometer – This eye pressure test is measured by the eye’s resistance to a puff of air emitted onto the eye.
- Applanation Tonometer – This method measures the amount of pressure needed to flatten the cornea by touching the eye’s surface after it has been numbed. While this is the most sensitive tonometer, a clear, regularly-shaped cornea is required for it to work correctly.
- Electronic Indentation – This test measures pressure by directly contacting the eye with a digital pen-like instrument.
Even though pressure testing is normally the first step in Glaucoma screenings, there are no specific levels of elevated eye pressure that definitively lead to glaucoma. And, at the same time, there are no lower levels of IOP that absolutely eliminate a person’s risk of developing glaucoma.
This is why early diagnosis and treatment is paramount in preventing vision loss due to Glaucoma.
Glaucoma Screening: Optic Nerve Health
The Optic Nerve is the part of the eye that normally suffers damage when eye pressure is too high for an individual eye to tolerate. To test this, the color and shape of the optic nerve will be carefully evaluated using an ophthalmoscope.
The ophthalmoscope works by lighting up and magnifying the inside of the eye so atrophy or cupping of the optic nerve can be evaluated. If the optic nerve is not a healthy pink color or appears to be cupped, additional tests will likely be run.
Glaucoma Screening: Field of Vision
Perimetry (or visual field testing) maps the entire field of vision for the forward-looking eye, including both central (straight-ahead) and peripheral (side) vision. This helps to identify any patterns and changes in peripheral vision, which is extremely important in diagnosing and managing glaucoma.
This test can sometimes be tedious for patients, but can normally be completed within 15 minutes using today’s advanced technologies.
Glaucoma Screening: Iris/Cornea Angle
Gonioscopy supports viewing the front part of the eye (anterior chamber) to check whether the angle where the iris meets the cornea is open or closed. This helps determine if patients are dealing with open-angle glaucoma or narrow-angle glaucoma.
To learn more, or to schedule a Glaucoma Screening, please Call (512) 528-1144 or Contact Us.