An Applanation Resonator Sensor for Measuring Intraocular Pressure Using Combined Continuous Force and Area Measurement

Abstract

In this study, the ARS method for measuring IOP was evaluated in an in vitro porcine eye model and showed high precision. The ARS method is, to the authors' knowledge, the first to combine simultaneous, continuous sampling of both parameters included in the applanation principle: force and area. Consequently, there is a potential for reducing errors in clinical IOP tonometry.

Increased Corneal Hysteresis After Corneal Collagen Crosslinking

“…The ART is a recently introduced tonometer 29,30 based on resonance technology. 31 A resonance sensor measures the contact area and a force transducer measures the contact force. Data for the contact area and contact force are sampled continuously (1000 Hz) during the corneal indentation, from the point the sensor contacts the cornea until the sensor is removed.…”

“…Data for the contact area and contact force are sampled continuously (1000 Hz) during the corneal indentation, from the point the sensor contacts the cornea until the sensor is removed. 31,32 A prototype of ART Servo with a servo-controlled motion of the sensor providing a movement toward the cornea was used in this study. A new algorithm for control of the sensor movement was implemented: when the full contact area is reached, the sensor immediately reverses and moves away from the cornea.…”

Can we trust intraocular pressure measurements in eyes with intracameral air?

“…Each porcine eye was fixed in the centre of a petri dish using agar gel (15 g/dm 3 ). To maintain reference pressure inside the eye, an established method was used where a thinwalled, winged cannula connected to a saline column was inserted through the sclera and into the vitreous chamber [11,12]. Cyanoacrylate adhesive glue (Loctite® 242, Henkel, Düsseldorf, Germany) was used to seal the interface between the sclera and the cannula to prevent leakage.…”

“…ART is a recently developed tonometry method [11,16,17]. It is slit-lamp-mounted, and based on resonance technique.…”

A comparison of intraocular pressure values obtained using a Goldmann applanation tonometer and a handheld version of applanation resonance tonometer: A preliminary report

“…The correlation between GAT-and ART-acquired readings was analyzed in many studies. [5][6][7] ART, as well as GAT, can be performed with the use of a slit lamp; it depends on the flattening of the desensitized cornea by an automatically exsertile tip. Three measurements of IOP are made, then averaged, but the contact time with the cornea is much shorter than during GAT, which greatly reduces the risk of cornea damage.…”