MEASUREMENT OF INTRAOCULAR-PRESSURE WITH A MODERN NONCONTACT TONOMETER

Purpose: To evaluate the intraocular pressure (IOP) in a population wi thout known glaucoma as measured by means of a noncontact tonometer (N CT). Methods: IOP values of 842 persons, measured by means of a Pulsai r 2000 NCT(R) (Keeler Instruments, Inc., Broomhall, Pennsylvania) by 5 investigators were evaluated. Three consecutive measurements were tak en first on the right eye and then on the left eye in each subject. To pical anesthesia Aias not used. Results: The distribution of the measu red IOP values was significantly different from a normal distribution. The median IOP was 15.0 mmHg (lower quartile/upper quartile 12.5/17.2 ). There were no differences in IOP values between male and female sub jects or between right and left eyes. There was no correlation between age and IOP values. Ninety percent of the subjects had an IOP within a range oi. 9-24 mmHg in both eyes. Among the examined subjects, the I OP was above 24 and 21 mmHg in 4,6 and 11%, respectively, in at least one eye. The median range of consecutive IOP measurements in one eye w as 3 mmHg (lower quartile/upper quartile 2.0/4.0). The median interocu lar IOP difference was 1.7 mmHg (0.7/2.7). The median individual coeff icient of variation (CV) values were 10.0% for the right eyes, -10.8% for the left eyes. Among the 5 different examiners, the IOP values, ra nge of 3 consecutive IOP readings in one eye, interocular asymmetry an d CV values were statistically comparable. Conclusion: The Pulsair 200 0 NCT is very simple to use and its handling is mostly independent of the operator. The results of the present investigation might be of som e value for future screening programs.