Evaluation of Changes in Intraocular Pressure with a Noncontact Tonometer in Healthy Volunteers

PURPOSE: We investigated whether or not intrasession or intersession fluctuations in intraocular pressure occur in healthy people using a noncontact tonometer. MATERIALS AND METHODS: A noncontact tonometer was used to measure intraocular pressure in the bilateral eyes of healthy subjects for 5 consecutive days. Paired t-tests and one- and two-way repeated-measures analyses of variance were performed for the acquired data. A p-value <0.05 was considered to indicate statistical significance. RESULTS: Eighty eyes of 40 healthy subjects were enrolled in the study. On day 1, intraocular pressure was significantly higher in the right eye than in the left eye (P = 0.014). The one-way repeated-measures analysis of variance revealed that intraocular pressure in the left eye was significantly lower on day 1 than on days 2 to 5 (P = 0.000–0.018); however, there were no significant differences among intraocular pressures measured on days 1 to 5 in the right eye. The two-way repeated-measures analysis of variance revealed no significant difference in intraocular pressure between the right and left eyes (P = 0.913). CONCLUSION: Although measurements using the noncontact tonometer were relatively stable, intraocular pressure was high on day 1.