It is a test that measures corneal thickness. It measures with ultrasound power. Corneal thickness is approximately 550 μm. It helps in glaucoma patients and in diagnosing ocular hypertension.

It can be used especially for intraoperative measurement of corneal thickness remaining after flaps removed by mechanical keratomes during EXCIMER LASER surgery.

It is used to measure whether corneal thickness is increased sufficiently with hypoosmosis riboflavin while crosslinking in keratoconus patients.