Abstract
Purpose :
The Ocular Response Analyzer (ORA; Reichert) uses a single air-puff to simultaneously measure intraocular pressure (IOP) and ocular biomechanical parameters. Either data from a single high-quality measurement, as indicated by a high wave score value, or averaged data from multiple measurements with different wave score values can be analyzed and interpreted. We tested whether the IOP and biomechanical outcome metrics from the ORA differ between the measurement with the highest wave score and the average of three measurements.
Methods :
Healthy subjects were prospectively recruited. Measurements of intraocular pressure (Goldmann-correlated IOP [IOPg] and corneal-compensated IOP [IOPcc]) and of ocular biomechanical parameters (corneal hysteresis [CH] and corneal resistance factor [CRF]) were made in triplicate in each eye of all subjects. Waveform parameters p1area, p2area, h1, h2, w1, and w2 were also collected. For each metric, outcomes from the measurement with the highest wave score were compared against averaged outcomes from three measurements of any wave score using paired t-tests (significance threshold α = 0.005). All values are mean ± standard deviation.
Results :
The Table contains the IOP, biomechanical, and waveform outcome metrics for the cohort (n = 396 eyes from 198 subjects; age = 38 ± 14 years). Wave score, corneal hysteresis, p1area, p2area, h1, and h2 were significantly greater for the measurement with the highest wave score, compared to the averaged measurement. IOPg, IOPcc, w1, and w2 were significantly lower for the measurement with the highest wave score, compared to the averaged measurement. There was no significant difference between the measurement with the highest wave score and the averaged measurement for CRF.
Conclusions :
There were statistically significant differences both in IOP outcome metrics and in biomechanical outcome metrics between the measurement with the highest wave score and the average of three measurements of any wave score. However, the magnitudes of these differences may be small enough to warrant the use of either measurement (i.e., the measurement with the highest wave score or the averaged measurement) in clinical or research settings, so long as one approach is used consistently.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.