Different Effects of Aging on Intraocular Pressures Measured by Three Different Tonometers

Abstract

This study aimed to compare intraocular pressures (IOP) using different tonometers, Goldmann applanation (IOPGAT), non-contact (IOPNCT), and rebound (IOPRBT), and to assess the effects of aging and central corneal thickness (CCT) on the measurements. The IOPGAT, IOPNCT, IOPRBT, mean patient age (65.1 ± 16.2 years), and CCT (521.7 ± 39.2 µm) were collected retrospectively from 1054 eyes. The differences among IOPs were compared by the paired t-test. Possible correlations between devices, age, and CCT were assessed by linear regression analyses. The effects of age and CCT on the IOP reading were assessed by mixed-effects regression models. The IOPGAT values were 2.4 and 1.4 mmHg higher than IOPNCT and IOPRBT, respectively; the IOPNCT was 1.0 mmHg lower than IOPRBT (p < 0.0001 for all comparisons). The IOPs measured by each tonometer were highly correlated with each other (r = 0.81–0.90, t = 45.2–65.5). The linear regression analyses showed that age was negatively correlated with IOPNCT (r = −0.12, t = −4.0) and IOPRBT (r = −0.14, t = −4.5) but not IOPGAT (r = 0.00, t = −0.2); the CCT was positively correlated with IOPGAT (r = 0.13, t = 4.3), IOPNCT (r = 0.29, t = 9.8), and IOPRBT (r = 0.22, t = 7.2). The mixed-effect regression models showed significant negative correlations between age and IOPNCT (t = −2.6) and IOPRBT (t = −3.4), no correlation between age and IOPGAT (t = 0.2), and a significant positive correlation between CCT and the tonometers (t = 3.4–7.3). No differences between IOPGAT and IOPRBT were seen at the age of 38.8 years. CCT affects IOPs from all tonometers; age affects IOPNCT and IOPRBT in different degrees. IOPRBT tended to be higher than IOPGAT in young subjects, but this stabilized in middle age and became higher in older subjects.

Comparison of Non-contact Tonometry and Goldmann Applanation Tonometry Measurements in Non-pathologic High Myopia

“…We reported that younger age and higher BMI were significantly correlated with higher IOP NCT but not IOP GAT , which is in line with previous studies ( 13 , 14 , 31 , 32 , 35 – 37 ). However, the Anyang Childhood Eye Study and NICOLA Study found that IOP increased with older age ( 34 , 38 ).…”

Comparison of intraocular pressure readings with Perkins, Tonopen, iCare 200, and iCare Home to manometry in cadaveric eyes

“…Even the studies that demonstrate good agreement between rebound tonometry, GAT and Tonopen note that greater variability exists at higher IOP and with variations in CCT [15][16]21] . Several studies have demonstrated a clear correlation between CCT and alterations in IOP readings with all forms of tonometry [24][25][26][27][28][29] . Tonnu et al [27] compared the effect of CCT on multiple methods of tonometry and noted that all methods of tonometry are significantly affected by CCT, however the effect is least with GAT.…”

It Is All about Pressure

“…Several studies have compared the performances of different tonometers, and how different variables can affect the accuracy. Sugihara and Tanito [13] analyze the effects of aging on IOP measured by three different tonometers. Corneal biomechanical properties change with age, which can differently influence the IOP measurement obtained with different devices.…”