Comparison of dynamic contour tonometry (Pascal®) with pneumotonometry and Goldmann tonometry

Abstract

To compare the intraocular pressure measurements as defined by the Pascal tonometer, the Goldmann tonometer and the pneumotonometer. METHODS: This was an observational clinical study, which included two hundred and five randomly selected subjects recruited from the Ophthalmology Department. The intraocular pressure measurements were performed with each tonometry technique in a randomized order. RESULTS: The Pascal's intraocular pressure measurement was significantly higher than that measured by the other two tonometers (p<0.05). The quality data of Pascal was: optimum in 27.3% (56 of 205 patients), acceptable in 42% (86 of 205 patients) and unacceptable in 23.4% (48 of 205 patients). In 7.3% (15 of 205 patients) it was impossible to obtain any measurement using Pascal. A weak correlation coefficient between the Pascal and the Goldmann, and between Pascal and the pneumotonometer was found. The Bland-Altman method of measurement using these tonometers showed a high degree of discordance. CONCLUSION: As reported by others authors, the Pascal's intraocular pressure measurement is higher than that of the Goldmann tonometer. The measurement differs from 0.7 to 4.4 mmHg. In corneas with pathology, it is very difficult or even unacceptable to measure the intraocular pressure using the Pascal tonometer.