The iCare Tonometer and the single-use probes are kept in Pyxis Medstation.
General considerations
The tonometer can be frustrating to get the hang of at first but once you have the knack of it, it is extremely easy to use.
How to use it
Press the measuring button (the oval-shaped lower button) to turn the tonometer on.
Once the display says ‘Load’ you may insert a single-use probe into the tonometer.
Once loaded, press the measuring button again. The tonometer is ready to use when ’00’ is displayed on screen.
Ask the patient to relax and to focus their vision on a point straight ahead. There is generally no need for topical anaesthetic drops.
Rest the tonometer gently against the patient’s face. The probe should be at 90 degrees to the eye and 4 to 8mm from the corneal surface. If needed, the top wheel can be turned to adjust the forehead support.
Lightly press the measuring button. The tonometer takes six readings and produces an average pressure measurement. Repeat steps 4 to 6 as needed until you have achieved six valid measurements.
There is no need to check the display after each measurement, as the tonometer will beep to indicate a successful or unsuccessful attempt. One short beep indicates a successful measurement. Two short beeps indicate an unsuccessful measurement. Reposition and try again. One long beep indicates that six valid measurements have been achieved. Check the display for the intraocular pressure determination.
The tonometer will automatically turn off after 2 minutes. If needed it can be turned off manually by pressing the selector button (the shell-shaped upper button) until ‘End’ is displayed and then pressing the measuring button for 2 seconds.
How to clean it
Standard surface wipes are sufficient to clean the tonometer casing.
Disassembly and cleaning of the probe base should only be performed by Biomedical Engineering personnel.
What the evidence says about it
Although not quite as accurate as Goldman applanation tonometry (the gold standard), the iCare rebound tonometer is useful for the purposes of screening where a precise value is not necessarily needed.
The tonometer is just as accurate in paediatric populations, including infants.
The iCare tonometer tends to slightly overestimate pressures, reducing the possibility of false negatives.
With these points in mind, an elevated iCare reading should generally be followed up by formal ophthalmological assessment of intraocular pressures.
