Introduction

The Tono-Pen Avia tonometer is a safe, reliable alternative to Goldmann tonometry, allowing you to safely and accurately measure intra-ocular pressure

Indications

1. Patient is unable to perform Goldmann tonometry
2. Irregular corneas

Contra-Indications

1. Allergy to any medications used during the procedure
2. Latex allergy

Materials

1. Ocu-Film tip cover
2. Proparacaine 0.5% ophthalmic solution (or other ocular anesthetic)

Setup

Verification

The Tono-Pen Avia must be verified (what used to be called “calibration” in the Tono-Pen XL) each day before it is used.  To perform verification:

1. Place an Ocu-Film tip cover on the unit
2. Point the measuring sensor towards the floor and press and hold the activation button for five (5) seconds.  The display will eventually read “dn” (which looks a lot like a lowercase “UP”)
3. After approximately 15 seconds, the unit will beep and the display will read “UP”.  Quickly move the measuring sensor to point towards the ceiling.
4. If calibration is successful, the display will read “Pass”.  Proceed to measurement.

Measurement

1. Place a new Ocu-Film tip cover on the instrument if necessary.
2. Instill one drop of proparacaine 0.5% ophthalmic solution in each eye
3. Press the activation button once.  The display will briefly show “88888”, followed by “====” and a beep.  Once you see the double bars and hear the beep, proceed to measurement.
4. Measure by tapping the measuring probe on the central cornea repeatedly.  A chirp will be heard after each successful measurement.  After 10 successful measurements, the unit will beep.  Measurements must be completed 15 seconds after the double bars appear.

Results

In addition to displaying the IOP (in mm Hg), a statistical significance indicator will appear in the display.  A statistical significance indicator of 95 indicates the 10 measurements had a standard deviation of 5%.

A statistical significance of “80” or “80-“ (measurements had a standard deviation of 20% or greater) requires a repeat measurement.

References

Reichert Tono-Pen Avia Tonometer Quick Reference Guide is can be found here

Reichert Tono-Pen Avia Tonometer User’s Guide is can be found here