CATS® Tonometer Prism
The New Shape of IOP.
A New, Modern, Patented Prism Designed for Your Goldmann Tonometer.
CATS® Tonometer Prism features a unique, patented, dual-curved surface design that successfully reduces measurement errors caused by corneal biomechanics, corneal thickness, and tear film, which affect a large percentage of patients.1-4 Simply replace your traditional Goldmann prism with a new CATS Tonometer Prism to instantly overcome these error-causing factors.2-4 CATS Tonometer Prism is made in the USA.
CATS Tonometer Prism is only available in the USA and can also be purchased from your Authorized Reichert Technologies Distributor. For US government sales, please call 1-888-849-8955 to place your order.
Why is CATS Tonometer Prism essential for your practice?
It is widely accepted that for eyes with average corneas, Goldmann tonometry provides reliable IOP measurements. However, we now know that corneal properties such as Central Corneal Thickness (CCT), Corneal Hysteresis (CH), and tear film vary significantly from average in a large percentage of patients. These variations in corneal properties result in a clinically relevant negative impact on Goldmann Tonometry. The use of CCT-based IOP correction formulas, to determine individual IOP values, is neither valid nor useful, and as such not helpful in glaucoma decision making.5-6
Modernize your Goldmann tonometer today with CATS Tonometer Prism.2-4
Respected glaucoma specialist, Nathan Radcliffe, MD, discusses the new and innovative CATS® Tonometer Prism, and how it can improve the care of glaucoma suspects and patients by providing IOP measurements less affected by corneal properties including corneal thickness, corneal hysteresis, and tear film.2-4,7,8
The Benefits of CATS Tonometer Prism with Nathan Radcliffe, MD.
The New Shape of IOP.
CATS Tonometer Prism features a unique, patented, dual-curved surface design that effectively reduces measurement errors caused by corneal biomechanics, corneal thickness, and tear film, which affect a large percentage of patients.1 Traditional Goldmann tonometer prisms "flatten" the cornea, which amplifies intracorneal stress during the measurement process. The curvature-matching design of CATS Tonometer Prism "cups" the cornea, reducing the impact of corneal thickness and corneal biomechanics on IOP measurements.2-4 In addition, CATS Tonometer Prism has a rolled outer edge which minimizes the tear film adhesion that affects traditional Goldmann prisms.2-4 Simply replace your traditional Goldmann prism with a new CATS Tonometer Prism to instantly realize the benefits of the CATS design.
Discussion of the CATS® Tonometer Prism with Andrew Rixon, OD, FAAO, and April Jasper, OD, FAAO
It is commonly known that Goldmann tonometry provides reliable IOP for average corneas. However, we also know that corneal properties vary significantly in patients, resulting in a negative impact on Goldmann IOP accuracy. CATS® Tonometer Prism – a new, modern, prism designed for your Goldmann tonometer – features a unique, patented, dual-curved surface which was engineered specifically to reduce measurement errors caused by corneal properties. Watch as Andrew Rixon, OD, FAAO, talks to host April Jasper, OD, FAAO, and discusses his experience with the CATS Tonometer Prism, and how this innovative tonometer prism has helped positively “shape” his Goldmann tonometry routine.
Designed to give you confidence in your Goldmann IOP readings.
In patients with average corneas, CATS Tonometer Prism will match traditional Goldmann prism IOP results closely because CATS Tonometer Prism was intentionally designed to measure the same as GAT in patients with average biomechanics and central corneal thickness. As patients’ corneal properties deviate from average, the difference between CATS and traditional Goldmann results will increase due to the ability of CATS Tonometer Prism to “ignore” corneal factors that produce IOP errors with the traditional Goldmann prism.2-4,7,8 CATS Tonometer Prism and traditional Goldmann prism produce similar measurements for normal corneas which ensures long standing IOP benchmarks of normal and high pressures are maintained, allowing clinicians to seamlessly integrate CATS IOP readings in comparison to their historic GAT IOP readings.2-4,7,8
Easily Integrate Into Any Practice.
CATS Tonometer Prism can be easily mounted on any Goldmann or Perkins tonometer. Simply replace your traditional Goldmann prism to immediately realize the benefits of CATS Tonometer Prism using the same technique you are already familiar with.2-4,7,8
Positioning that Self-Centers.
The flat surface of a traditional Goldmann prism tip permits IOP error resulting from sub-optimal positioning, because it is subjectively placed on the cornea. Due to the curvature-matching surface, CATS Tonometer Prism self-centers on the cornea, providing clearer and sharper mires when positioned on the apex of the cornea. Improper placement of CATS Tonometer Prism on the cornea results in obviously skewed mires which will not intersect for measurement. This immediately prompts the clinician to re-position the tip with perfectly centered mires on the corneal apex, which ensures optimal accuracy and repeatability of IOP measured by CATS Tonometer Prism.
CATS Tonometer Prism Centration Video
See how easy the intuitive CATS Tonometer Prism is to use, by seeing the mires up close in this brief and descriptive video. CATS Tonometer Prism is specially designed to eliminate subjective alignment errors.
'1 - McCafferty S, Lim G, Duncan W, et al. Goldmann tonometer prism with an optimized error correcting applanation surface. Transl Vis Sci Technol 2016; 5:4–5.
2 - McCafferty S, Tetrault K, McColgin A, Chue W, Levine J, Muller M. Modified Goldmann prism intraocular pressure measurement accuracy and correlation to corneal biomechanical metrics: multicentre randomised clinical trial. Br J Ophthalmol. 2019 Dec;103(12):1840-1844. doi: 10.1136/bjophthalmol-2018-313470.
3 - McCafferty S, Lim G, Duncan W, et al. Goldmann tonometer error correcting prism: clinical evaluation. Clin Ophthalmol 2017;11:835–40.
4 - McCafferty S, Enikov E, Schwiegerling J, et al. Goldmann tonometry tear-film error and partial correction with a shaped applanation surface. Clin Ophthal 2018;12:71–8.
5 - Pg 18. Robert N. Weinreb, James D. Brandt, David Garway-Heath and Felipe Medeiros, World Glaucoma Association on Intraocular Pressure; Consensus Series 4; May 5, 2007
6 - Brant JD, Gordon MO, Gao F, Beiser, JA, Miller JP, Kass MA. Ocular Hypertension Treatment Study Group, Adjusting intraocular pressure for central corneal thickness does not improve prediction models for primary open-angle glaucoma. Ophthalmology. 2012 Mar; 119(3): 437-42. doi: 10.1016/j.ophtha.2011.03.018.
7 - McCafferty S, Levine J, Schwiegerling J, et al. Goldmann applanation tonometry error relative to true intracameral intraocular pressure in vitro and in vivo. BMC Ophthalmol 2017;17
8 - McCafferty S, Levine J, Schwiegerling J, et al. Goldmann and error correcting tonometry prisms compared to intracameral pressure. BMC Ophthalmol 2018;18.
CATS® Tonometer Prism is distributed by Reichert Technologies · CATS is a registered trademark of CATS Tonometer, LLC · CATS Logo is a registered trademark of CATS Tonometer, LLC
Dimensions: 12.3 mm (W) x 29.9 mm (L)
Weight: 1.63 g