[Mobile intraocular pressure measurement. From palpation to initial clinical experience with the handheld dynamic contour tonometer].

Goldmann applanation tonometry is still the gold standard of intraocular pressure measurement (IOP) and an essential part in the diagnosis of glaucoma. Applanation tonometry is usually performed on a sitting patient at the slit lamp. However, under certain circumstances it is necessary to measure the IOP outside the office setting. With handheld devices the measuring procedure is brought to bedside and surgery theatres, as well as to patients who are not able to sit behind the slit lamp. The dynamic contour tonometer (DCT) represents a new method of direct IOP measurement. Its physical principle is based on piezo-electronic contour matching tonometry and is claimed to be less dependent on biochemical properties of the cornea. Besides the IOP, the ocular pulse amplitude can also be measured. Until now, the DCT had been available as a slit lamp mounted device. In this report, we present a portable prototype of the device. In comparison with the Perkins tonometer and the TONO-PEN XL, the handheld DCT shows smaller intra- and inter-examiner variability. Additionally, the device offers the unique possibility to display the ocular pulse amplitude while the patient is in a horizontal position.