Monitoring daily intraocular pressure fluctuations with self-tonometry in healthy subjects

To evaluate the accuracy of the intraocular pressure (IOP) measured by healthy subjects with icare^® Home and to observe the IOP fluctuation and pattern of IOP fluctuation in healthy subjects over three consecutive days.

Sixty healthy subjects were recruited to the study. IOP was measured by the subjects themselves and by study staff using icare^® Home tonometers on visits 1 and 2, as well as by study staff using Goldmann applanation tonometry (GAT). Furthermore, the subjects measured their IOP at home for three consecutive days.

Twenty-three per cent of the study eyes were excluded in the statistical analysis due to dropout or non-compliance to the schedule. Approximately 70% of the icare^® Home measurements were within 3 mmHg of the GAT measurements. Ten to 16% of the study eyes had IOP peaks outside office hours. Sixty-three per cent of the study eyes had different IOP patterns on consecutive days.

Rebound self-tonometry appears to be accurate and could be used to monitor short- and long-term IOP variations. The difference between IOP patterns on consecutive days raises questions as to the certainty of a single IOP measurement as a measure of treatment effect.