Tonometer probes – which is best?

There are two types of probes which can be used for Goldmann tonometry.

Traditional Goldmann tonometer doubling prism

  • Reusable – Suggested replacement every 2 years or by the date stamped on the probe.
  • Approx £100-£140 per probe.
  • Requires safe disinfection practices.

Disposable Tonosafe probes

  • Disposable ‘one use’ probe.
  • Approx £80-£100 for 100 probes.
  • Requires safe disposal practices.

The probe which you choose will depend on how often you intend to use your Goldmann tonometer, as well as general personal preference. The traditional doubling prisms tend to be easier to use and better if you intend to use your tonometer regularly, due to being more cost effective. The Tonosafe probes are more convenient with regards to disinfection, but are costly and (I find) harder to use due to the additional ‘skirt’ around the probe.

  • Traditional Goldmann tonometer prism disinfection: The College of Optometrists recommends Sodium Hypochlorite 1% for disinfection of Goldmann reusable probes. Follow this procedure:
    1. After use, rinse for at least 30 seconds in saline.
    2. Soak in Sodium Hypochlorite 1% solution (e.g. Milton) for at least 10 minutes.
    3. Rinse in saline again for at least 10 minutes.
    4. Dry with a clear tissue.
    5. Re-use immediately or store dry.
  • Safe disposal of Tonosafe probes: Used Tonosafe probes are considered ‘offensive waste’. They can be disposed of in a yellow medicine disposal box or a yellow and black striped bag, also known as a ‘tiger bag’. Optometrists wishing to use Tonosafe probes should contact their waste contractor for supply of either of these to ensure their waste is disposed of responsibly.

More information on probe disinfection and probe disposal can be found on The College of Optometrists Guidance website.