This test is ordered when the physician is unable to get a clear view of the inside of the eye, which may be due to a dense cataract, hemorrhage or corneal edema. The B-scan can also rule out a retinal detachment or swollen optic nerves.
Typically performed while the patient is laying down, a probe with clear gel is applied to the eye, usually on the closed lid. This is a very easy test however the B-scan occasionally needs to be done on the globe of the eye. For this the eye is anesthetized and the probe scans the open eye if the lid is blocking the necessary view.