Tonometry comparison: Goldmann versus Tono-Pen

Tono-Pen and Goldmann tonometers were compared in 152 eyes of healthy subjects (Group A) and 69 eyes of patients after intraocular procedures (Group B). In Group A, the readings from both the tonometers showed no statistically significant difference in the 0 to 15mmHg range. However, the Tono-Pen values were lower in eyes with intraocular pressures between 16 and 30mmHg (P less than .0001). This questions the reliability of Tono-Pen as an adequate screening instrument. The correlation between the two instruments was acceptable in Group B (r = .89), indicating that the Tono-Pen may be used cautiously to determine intraocular pressure in postoperative patients.