Hand-held dynamic contour tonometry

Abstract

ABSTRACT.Purpose: We present a prototype of the hand-held dynamic contour tonometer (HH-DCT) and prospectively compare this HH-DCT with the well-established Perkins applanation tonometer (PAT) and the TonoPenXL (TPXL). Methods: In a prospective, single-centre, randomized study, intraocular pressure (IOP) readings were taken in random order using HH-DCT, PAT and TPXL tonometers. Intra-observer variability was calculated for each observer and compared between three experienced ophthalmologists and an inexperienced medical student. Results: Ninety-two corneas of 92 healthy participants were enrolled. IOP [mean mmHg ± standard deviation (SD)] as measured by HH-DCT was 16.97 ± 2.71, by PAT 13.98 ± 2.52 and by TPXL 13.34 ± 2.68. The range of three consecutive IOP readings differed significantly between the devices [p < 0.001; mean range: 1.45 ± 1.07 (HH-DCT), 1.87 ± 0.97 (PAT) and 2.08 ± 1.77 (TPXL)]. There was no difference of the range in all devices between the ophthalmologists and the medical student (HH-DCT p = 0.68, PAT p = 0.54, TPXL p = 0.48). Conclusion: IOP readings measured by HH-DCT are significantly higher than by PAT and TPXL. The differences of IOP measurements are in good accordance with previous studies using the slit-lamp-mounted DCT (SL-DCT) and Goldmann Applanation Tonometry, where SL-DCT readings were 1-3.2 mmHg higher. HH-DCT seems to give more constant results, which can be seen in the lower intra-observer variability compared to PAT and TPXL.

Intraocular Pressure During Robotic-assisted Laparoscopic Procedures Utilizing Steep Trendelenburg Positioning

“…The variability of tonometry measurements, 1 to 3 mm Hg, is also a limitation. 14,26 Again, when taken in the context of the large increase in IOP seen while in sTBURG, this variability is not likely to alter the significant results. The study is also limited by a failure to reach the desired number of subjects in the control groups (group 2, group 3) secondary to slow accrual; however, power > 90% was still achieved based on post hoc power analysis with significance maintained at a = 0.05.…”

Precision and accuracy of the ICare tonometer – Peripheral and central IOP measurements by rebound tonometry

“…Also, the time needed to apply anaesthetics and fluorescein, to make regular calibration checks and to set up the tonometer can add up. There are many alternatives to the GAT (Knecht et al. 2009).…”

Sinken des Augeninnendrucks und der okularen Pulsamplitude während der Intubationsnarkose

“…Außerdem konnte dargestellt werden, dass auch das handgehaltene DCT sehr genaue Messwerte verglichen mit dem Spaltlampen-montierten DCT sowie GAT lieferte [12].…”