How It Feels
Gonioscopy does not usually cause any
discomfort. The eyedrops used to numb your eye may burn a little. You may find
it hard to keep from blinking during the test.
If your pupils were dilated, your vision may be
blurred for several hours after the test. You should not rub your eyes for 20
minutes after the test, or until the medicine wears off.
also a very small risk of an eye infection or an
allergic reaction to the eyedrops used to numb your
Gonioscopy is an eye examination to look
at the front part of your eye (anterior chamber) between the
cornea and the
iris . During gonioscopy, the drainage angle of your
eye is checked. Your doctor measures the drainage angle, its width, and checks
whether it is open or closed.
The drainage angle
appears normal, is wide open, and is not blocked.
The drainage angle looks narrow, is a slit, or is closed. This means that the angle is partially or completely blocked, or there's a risk that the angle will close in the future.
A partially or completely blocked drainage angle may mean that you have closed-angle glaucoma . There are many reasons that a drainage angle can be blocked. These include scar tissue, abnormal blood vessels, injury or infection, and extra color pigment of the iris.
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- You cannot sit or lie still during the
- You have an allergy to the medicine used to numb your eye
during the test.
What To Think About
Other tests may be done to check
for glaucoma or other eye problems. These tests include a slit lamp
examination, tonometry (which measures the pressure inside the eyeball),
ophthalmoscopy (which checks the optic nerve), and perimetry (which tests side
To learn more, see:
Ramos-Esteban JC, et al. (2009). Clinical examination of glaucoma. In M Yanoff, JS Duker, eds., Ophthalmology, 3rd ed., pp. 1117–1127. Edinburgh: Mosby Elsevier.