Glaucoma an lead to permanent vision loss and your eye doctor will likely want a few glaucoma tests done regularly. I am going to talk about these tests and why the optometrist or ophthalmologist is running them:
What Glaucoma Tests Will the Eye Doctor Want?
- Gonioscopy
- Pachymetry
- Visual Field
- Intraocular pressure or eye pressure
- Optic nerve scans
Who Performs Glaucoma Tests?
Typically a technician will perform the test and either an optometrist or ophthalmologist will interpret the results. Sometimes the eye doctor will need to do some adjustments to the test or will perform the test.
Glaucoma Tests Details:
Gonioscopy
This test shows how open or closed the area that drains the fluid from your eyes is. It looks at the angle where your cornea, the clear part where a contact lens sits, meets your iris, the colored part of the eye.
This can be done a few different ways. One way is with a gonio lens. This is a lens that the eye doctor will put directly onto the eye after numbing it and look at the angle. Another way is done using an ocular coherence tomographer taking a picture of that area and then measuring the angle from that image.
Pachymetry
Now, I will forever think of elephants due to my glaucoma professor having a slide with an elephant on it when introducing us to pachymetry. After all, they are pachyderms. While pachymetry is measuring the thickness of the cornea it sadly has nothing to do with elephants. This test measures the thickness of your cornea. Research has shown that there is a strong correlation with thin corneas and glaucoma. This can be done with either an ultrasonic device touching the cornea after it has been numbed, or by using an ocular coherence tomographer taking a scan and then measuring from the image.
Visual Field Test
Next, is the visual field. This will look at the function of your vision from a glaucoma standpoint. Glaucoma makes you lose your side vision first and this is a reliable way to monitor if any loss has occurred. This glaucoma test can be done with a ton of different machines and a ton of different ways.
Eye Pressure Check
So, glaucoma is when the pressure inside the eye is too high for the eye to handle. So, it makes logical sense that we would want to monitor that pressure. This can be done with a bunch of different devices. The puff of air or NCT is the most feared and thankfully most clinics have moved away from it. Goldmann is another way and was considered the gold standard for a long time. Newer research has shown that the iCare is more accurate. The iCare has a small probe that is too small for the eye to feel it touching it. The device measures how long it takes for the probe to rebound after touching the cornea.
Optic Nerve Scans
This is probably to most valuable piece of information to the eye doctor when it comes to glaucoma. An ocular coherence tomographer will scan the optic nerve and identify how thick your retinal nerve fiber layer is. If we are losing nerve fibers faster than we should then the eye doctor will know to adjust treatment. There are other things given by this scan, but I will avoid the extreme nerd talk for today.
What Happens After My Testing?
Now, the eye doctor will go over the glaucoma test results and depending on the findings either start you on some glaucoma eye drops or recommend surgery. The eye doctor will likely want to follow you somewhere between every 3 months and every 6 months depending on the severity of the disease. The tests are all noninvasive and easy to do, so you should be able to drive afterwards. The worst case scenario is you had to be dilated for the eye doctor to get accurate results.