Henry Ford wrote a book in which he claimed that the key to success for businesses was to focus solely on the product and nothing more. Something that is easily said from someone whom replaced the horse and buggy with internal combustion vehicles offering extraordinary convenience to the West. This translates well into an analogy for Icare- a Finnish company that prior to their tonometric invention had largely been an unknown. Realizing that no practical tonometry method existed, Rebound Tonometry came without the need for drops or air-puff or fear for that matter. IOPs could now be obtained (accurately) with five light-touches of the cornea; practically unnoticeable and completely painless. For the most part, we agree with those claims and find them mostly to be true– the ICare is a amazing feat of technology that bypasses the air-puff and need for numbing drops altogether. But of course, there is a price that must be paid. We find that the Icare requires some user skill/experience to use, and for uncooperative patients, it may take a few tries to get reliable readings (in between the blinks and lashes). The device can also be intimidating despite not blasting air to the cornea, it does still make contact with the cornea with the use of a tiny probe, and depending on the tear film, can feel sticky or slightly aggressive. Above all though, the Icare is not as efficient as a Non-contact tonometer would be. Since it’s a handheld device, IOPs can be taken anywhere however that doesn’t mean it will mesh well with your current pre-test environment (given desktop instruments). In the absence of an experienced operator, expects IOPs to take longer.
OUR TAKE: A triumph for tonometry that avoids the numbing and air-puff, yet lacks efficiency in office settings. As accurate as your Goldmann with higher patient compliance.
#1. What is Rebound Tonometry?
Unlike Non-Contact Tonometry, or Goldmann Applanation Tonometry, the iCare utilizes a very lightweight and ergonomic probe that momentarily makes contact with the cornea. The instrument’s software records and analyzes the effect caused by each rebound, and produces a reading (in mmHg) indicating a measure of pressure. The eye’s intra-ocular pressure (IOP) has an effect on the rebounding of the probe, and therefore can be measured by the analyzation of the probe’s contact with the eye. Rebound tonometry is unique in that no puff of air is utilized, and despite contact with the cornea, no anesthetic drops are required. Patient’s describe rebound tonometry as a soft feather gently bumping the eye; some patients do not observe a corneal reflex reaction. As mandated by the FDA, rebound probes are single use, and are typically made from the same material as your Goldmann applanation tips.
#2. Accurate In Comparison
The Icare has undergone multiple clinical studies indicating the instrument is within 1.2mmHg (average) of a properly performed Goldmann Applanation Tonometry exercise. In our own unofficial testing of the Icare, we found central IOPs (straight 2mm from the nasal and temporal limbus) to slightly overestimate IOPs by a mean of 2mmHg. The Icare as a screening IOP device is an accurate option, however is not as accurate as Goldmann Applanation Tonometry (GAT).
There are other portable tonometers; the TonoPen XL, and the Diaton, however none are as portable and as easy to use as the Icare. Requiring no drops, the Icare can be used on virtually any patient, in virtually any position. Even elderly patients whom are bound to horizontal positions can be tested without strain. The Icare’s battery supply should last several months (with normal daily use) and requires no recharging or corded power supply.
It does not have a built-in printer, nor does it have the availability to wirelessly print via bluetooth. All results must be recorded by the operator.
It does store the last 10 measurements, however it will not save patient information.
No. The procedure for both eyes is identical. There is no input required prior or post test.
Yes. The device takes 5 consecutive measurements, and averages the 5 IOPs to read the mean measurement on the analog screen.