Measuring corneal thickness with ultrasonic waves. Pahimetry is mandatory for comprehensive examination of glaucoma, as the thickness of the cornea is important for the exact value of the measured intraocular pressure. Thicker corneas gives false high values and vice versa, thinner gives false low values. Corneal thickness is important also for the procedures used for changing the corneal refraction. In our clinic for pahimetry is used Ocusca.