TONOMETRY WALKING ON AIR
At the 1972 World’s Fair, Dr. Bernard Grolman of Reichert (formally American Optical) debuted his invention, the Non-Contact Tonometer (shown at right). At the time, the law didn’t permit clinicians without a medical degree to administer topical anesthetics, so optometrists couldn’t perform Goldmann tonometry—the only method available to determine intraocular pressure (IOP). Dr. Grolman felt the solution lay in the power of an air pulse. The air pulse in the NCT I, and its later version, the NCT II, created in 1982 (shown at left), had to produce enough force to push the cornea past applanation into a slight concavity. Using time as a correlate of IOP, the longer it took for the applanation to occur, the higher the pressure. Dr. Grolman’s invention finally gave optometrists the ability to measure eye pressure without anesthetic, making the NCT I an immediate success and paving the way for today’s modern NCTs, which now use highly accurate pressure transducers to measure the actual force in the air pulse, rather than time.
Courtesy of Reichert, Inc.