Spotlight ON TECHNOLOGY & TECHNIQUE

A Tonometer Based on a New Measuring Principle

By Leslie Goldberg, Associate Editor

The iCare-Tonometer (Tiolat, Helsinki, Finland and distributed in the U.S. by Rhein Medical) is based on a new measuring principle, in which a very light probe is used to make momentary contact with the cornea. The measurement is barely noticed by the patient and often does not cause corneal reflex, according to the company.

Physician Feedback

"The gold standard for assessing intraocular pressure is still Goldmann applanation tonometry," says Richard S. Hoffman, M.D., clinical associate professor of Ophthalmology at the Casey Eye Institute, Oregon Health and Science University. "However, we routinely use a [competitor's hand-held tonometer] for postoperative pressure checks and routine screenings. One of the problems we have found is that the measurements many times did not correlate well with Goldmann tonometry. There might be a 5 to 7 mmHg difference between the two."

The iCare Tonometer has appeared to correlate much closer to Goldmann applanation, says Dr. Hoffman. "The ‘no-drops’ feature is really not a major advantage of the device because we many times have to place anesthetic drops to dilate our patients anyway. But it can be used on small children without the use of anesthetic drops and this has been useful in postoperative children where we do not want to upset them with anesthetic drops."

Dr. Hoffman has also found the device to be very useful for uncooperative patients, including children, adults with dementia and obese patients where it is difficult to get their head into a slit lamp.

Dr. Hoffman has a 58-year-old Down's patient who required a corneal transplant for keratoconus. "After 4 years of treating this patient, I have only been able to examine him with a hand-held slit lamp," says Dr. Hoffman. "He will not put his head in a slit lamp and a measurement with [the other hand-held tonometer] is impossible due to his disability. When we first got the iCare tonometer, one of our technicians was able to get an accurate measurement without disturbing him at all. It was quite impressive."

The only disadvantage Dr. Hoffman sees with the device is the inability to measure intraocular pressure when the patient is in a supine position. "Intraoperative measurements and measurements of children under general anesthesia are not possible without sitting the patient upright," says Dr. Hoffman. "But we've been very happy with the device so far."

Other Advantages of the iCare Tonometer

► No anaesthetic is needed

► The rapid measurement is suitable for noncompliant subjects

► The device is small, handheld and portable

► The method is proven to be accurate and comfortable; only a small force is applied to the eye

► The single-use, disposable probe guarantees microbiological safety. OM

For more information on the Icare Tonometer, visit Rhein Medical at www.RheinMedical.com or call (813) 885-5050.