How to use the Reichert Tono-pen AVIA:
1) Put on the protective cover. Make sure not to make it too tight or too loose.
2) Press the blue button once. You will hear one beep. The green light will turn on and the screen will show a series of dashed lines in the bottom right corner.
3) Hold the Tono-pen perpendicularly to the corneal surface. Tap gently and try to avoid wild variations in the pressure you apply between taps. For each tap that is recorded, a number will appear in the bottom right corner. You need 10 in total. The final reading will look like this:
The larger number is your pressure reading. The smaller number is your confidence interval.
Video on how to use the Tono-pen: https://youtu.be/Hqcf9Ll-pl0
Notes:
The Tono-pen is gravity independent and patient does not have to be any particular position for this to work.
If you are using your fingers to spread apart the eyelids, be sure your fingers are on a bony surface and that you are not pressing on the eye itself as this will give you a falsely elevated reading.
Having trouble getting accurate readings with the Tono-pen? Try calibrating it before using:
1) Hold Tono-pen with the tip pointing downwards. Hold down blue button for 5 seconds. You should hear 5 beeps in succession.
2) The display will now show “dn” which is Tono-pen code for “down.” Continue to hold with the tip downwards until the screen changes to “UP.”
3) Quickly and smoothly flip Tono-pen so that the tip is now upwards until the screen says “pass” or “fail.” If it says “pass” then you’re done. If it says “fail” you can repeat the calibration steps above. If it continues to say “fail” after multiple attempts, the device may require servicing.
Tono-pen calibration video: https://www.youtube.com/watch?v=y1Mg5Zkr-qE&feature=youtu.be