What is eye biometry?
This is a test to measure the shape and size of the eye. It is commonly used to calculate the power of intraocular lens (IOL) implants required for cataract and refractive surgery. Biometry can be performed using either optical coherence interferometry or ultrasound technology.
How is it done?
Using an IOL Master, the non-invasive test is performed by placing your chin on the instrument chin rest and focussing on a target light. It takes only a few minutes to perform.
Ultrasound biometry is used for patients who have dense cataracts where measurements on the IOL Master are not possible. This test involves placing an ultrasound probe on the surface of the cornea to obtain measurements of axial length. These can then be used along with keratometry measurements to calculate IOL lens powers. A local anaesthetic eye drop is inserted into the eye before this test is performed.
Before your appointment:
Whether we use the IOL Master or the ultrasound biometer it is important to remove your contact lenses prior to the measurements being taken.