A comparison of three different tonometric methods in the measurement of intraocular pressure in the pediatric age group

To compare intraocular pressure (IOP) measurements obtained with non-contact tonometry (NCT), Icare rebound tonometry (IRT) and Goldmann applanation tonometry (GAT) in pediatric cases and to examine the effect of topical anesthesia on measurements obtained using IRT.

Pediatric cases in a healthy general condition and with ophthalmic examination findings within normal limits were included in the study. IOP measurements were taken with NCT and IRT devices in all cases. Topical anesthesia was subsequently applied, and IOP measurements were then repeated using IRT and GAT tonometer devices. Differences between measurements were subjected to statistical analysis.

One hundred ten eyes of 55 patients, 27 male, with a mean age of 11.44 ± 2.31 years (7–17) were included. Mean pre-anesthesia IOP values were 16.47 ± 2.89 mmHg with NCT and 17.49 ± 2.57 mmHg with IRT. Mean IOP values after topical anesthesia were 16.91 ± 2.17 mmHg with IRT and 15.51 ± 2.41 mmHg with GAT. IOP measurement values obtained with all three devices exhibited positive correlation with central corneal thickness values. Statistically significant correlation was present in terms of IOP measurement values between all three devices. However, IOP values obtained with the three devices exhibited statistically significant differences. The application of topical anesthesia caused a statistically significant decrease in IRT measurements; however, statistically significant this small change (0.58 mmHg) in recorded IOP would not be considered clinically significant.

IOP measurements obtained with NCT, IRT and GAT devices in the pediatric age group correlate with one another, but differ from one another in a statistically significant manner. Application of topical anesthesia affects IRT measurements; however, these small changes would not be considered clinically significant.