Physiological short‐term variability of ocular pulse amplitude (OPA) measured by dynamic contour tonometer (DCT) in healthy subjects

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Abstract Purpose The Pascal® dynamic tonometer is a new non‐applanation contact tonometer designed to be largely independent of the structural properties of the cornea. It measures the systolic and diastolic IOP and their difference to determine OPA. By recording the pulsatile component of ocular blood flow (heart pulse as a function of time) the OPA could provide an indirect measurement of the choroidal perfusion. It has been suggested that OPA could be an indirect risk factor for glaucoma progression. We aimed to assess the short‐time variability of OPA in healthy persons Methods The left eyes of 30 healthy subjects were included in this prospective study. The IOP was measured twice by Goldmann applanation tonometers (GAT) followed by 3 consecutive measurements by DCT 10 min later. Pachymetry, arterial blood pressure and pulse rate were measured after IOP measurements. These measurements were repeated with an interval of fifteen days at the same hour of the first measurements. The mean value of each parameter was taken into account for the statistical analysis. Student Test was used to assess the difference and the Pearson correlation was used to assess the correlation between the various parameters Results The mean age was 41 ± 12 years. The mean IOP at the first visit was 13.6 ± 2.9 mmHg by GAT and 14.3 ± 2.2 mmHg by DCT. The mean OPA was 2.4 ± 0.9 mmHg (0.8 to 4.3 mmHg) at the first visit. The mean IOP at the second visit was 13.4 ± 3.2 by GAT and 15.0 ± 2.5 mmHg by DCT. The mean OPA was 2.6 ± 1.0 (0.9 to 5.8) mmHg at the second visit. Conclusion There was no significant difference in both OPA measurements. This parameter remains stable in a short‐time interval in healthy subjects.