These two types of ultrasound scans give us a 2-dimensional picture of the inside of the eye, and provides a different view of structures we can see through the microscope.
B-scan: We use this scan to evaluate posterior structures such as the retina. It is especially useful when certain structures, such as a dense cataract, block our view when we examine through the normal slit-lamp microscope in the clinic.
For the B-scan procedure, an anaesthetic drop will be applied to the surface of your eye which takes effect immediately and lasts about 20 minutes. It will not affect your vision. A tear gel is applied to the probe tip and you will feel a cool sensation on and around your eye.
UBM: We use this scan for structures at the front of the eye, such as the cornea and iris. For the UBM procedure, a water bath system is used for the test. Results are viewed on a computer and available immediately.
Both these tests are useful for making clinical diagnoses and in planning surgery.