Corvis ST Tonometry and Pachymetry

Purpose:

It is important to correctly assess the intraocular pressure of the eye. Conventional applanation tonometry readings can be affected by the thickness of the cornea: a thicker than average cornea can give artificially high readings and thinner corneas, lower pressure readings. The Corvis® ST mitigates this problem by simultaneously measuring the thickness of the cornea (pachymetry) and calculating the correct pressure. To do this, it records the reaction of the cornea to a defined air pulse using a high-speed Scheimpflug camera. This camera captures over 4300 images per second, permitting highly precise measurement of IOP and corneal thickness. Based on a video of 140 images, taken within 31 ms after onset of the air pulse, the Corvis® ST provides a detailed assessment of corneal biomechanical properties.

Procedure:

The patient places their chin on a chin-rest and fixes their eye on a light or "fixation point" ahead of them. The device releases a short burst of air at the eye and the result is displayed on the operator console.

How Long Does This Take?

A single pressure measurement takes about 5 minutes. AM phasing will take all of the morning and All Day phasing will take from 9:30 until 16:00