Since intraocular pressure (IOP) is the second most critical metric next to visual acuity for assessing the ocular health of a patient, the design of the CATS® Tonometer Prism has the potential to greatly enhance clinical care through accurate IOP measurement. The CATS® Tonometer Prism has been cleared by the FDA for sale in the United States in both reusable and single-use, disposable versions. Measurement of IOP is not only critical to the accurate diagnosis of ocular disease, but it also is a necessary guide for effective treatment strategies. The CATS® Tonometer Prism is designed to deliver accurate IOP measurement through an easily adopted modification to the surface of the GAT prism. Additionally, the implementation is easy by simply changing the GAT’s tip.  There is no change to existing practitioner protocol and the cost difference is minimal.

The CATS® Tonometer Prism is designed to establish a new standard in reliable Goldmann IOP measurement accuracy.

Multiple scientific studies demonstrated the performance of the CATS® prism. The peer-reviewed publications included a:

  • Direct comparison of the CATS® Prism to the GAT prism
  • Human cadaver eye intracameral pressure transducer comparison of the CATS® and GAT prisms
  • An intracamerally placed pressure transducer comparison of the CATS® and GAT in live human eyes
  • Tear-film hydrostatic study

All studies confirmed our original mathematical modeling design predictions developed in a National Institute of Health, SBIR Phase I grant. Please refer to a complete listing of our publications here.  Click to view our White Paper and Technical Q&A.

Our presentations on this topic won “Best Paper of Session” two times at the American Society of Cataract and Refractive Surgery (ASCRS) Conference. Additionally, presentations were made at Association for Research in Vision and Ophthalmology (ARVO), American Academy of Ophthalmology (AAO), European Society of Cataract and Refractive Surgery (ESCRS), American Academy of Optometry (AAOpt), and the American Glaucoma Society Annual (AGS) meetings. Our research scientists have published in many scientific journals and presented at scientific conferences as described in the Events & News tab of our website.


The CATS® Tonometer Prism’s advanced technology coupled with its improved ergonomic function and aesthetic appeal provides complete clinical ease of use.