Lower variability in measurements and better interoperator and interdevice reproducibility suggest that rebound tonometry may better characterize changes in intraocular pressure (IOP) in time compared with Goldmann tonometry, according to research results published in the Journal of Glaucoma.
In a series of 3 prospective, cross-sectional studies, researchers sought to evaluate the intraoperator, interoperator, and interdevice variability associated with a rebound tonometry device.
Participants included consecutive adult patients who presented at the West Virginia University Eye Institute during the enrollment period for the studies, who were to undergo IOP measurements using Goldmann tonometry during their scheduled examinations. Anyone presenting with corneal or ocular pathology was excluded.
In total, 28 participants were enrolled in the first study, 19 in the second, and 25 in the third. Across all 3 studies, participants were White women aged 70 years or older. Mean central corneal thickness was in the normal range.
In the first study, investigators randomly assigned 13 right eyes and 15 left eyes to undergo rebound tonometry, while fellow eyes underwent Goldmann tonometry. Mean IOP in rebound eyes was 16.5±4.6 mm Hg, and 15.5±3.0 mm Hg in rebound and Goldmann eyes, respectively. Overall within-subject variance in rebound tonometry measurements was 0.757, while variance was 2.471 in Goldmann tonometry eyes—leading to a statistically significant, 70% lower within-subject variance in rebound tonometry vs Goldmann tonometry. This difference was indicative of better intraoperator reproducibility of rebound measurements.
In the second study, mean IOP was 16.6±3.0 mm Hg and 16.5±3.0 mm Hg measured with rebound tonometry. There were no mean IOP differences in either eye between operators, and agreement of rebound tonometry measurements among all 3 operators was good (right eye ICC, 0.78; 95% CI, 0.60-0.85; left eye ICC, 0.75; 95% CI, 0.50-0.83).
In the third study, mean IOP was 15.6±4.3 mm Hg and 15.4±4.3 mm Hg in right and left eyes, respectively. There were no differences in mean IOP in either eye between devices. Rebound measurement agreement across 3 devices under a single operator was good, approaching excellent (right eye ICC, 0.87; 95% CI, 0.83-0.90; left eye ICC, 0.89; 95% CI, 0.86-0.91).
“[Rebound tonometry] demonstrates significantly greater precision than Goldmann tonometry, with good interoperator and interdevice reliability,” the researchers report. “[The] lower measurement variability suggests that it can characterize IOP changes over time more robustly than Goldmann tonometry, aiding clinicians in assessing the effectiveness of therapy and the consistency of IOP control in patients with glaucoma.”
Realini T, McMillan B, Gross RL, Devience E, Balasubramani GK. Assessing the reliability of intraocular pressure measurements using rebound tonometry. J Glaucoma. 2021;30(8):629-633. doi:10.1097/IJG.00000000000001892