Rebound tonometry demonstrates high correlation and moderate agreement with applanation tonometry for measuring intraocular pressure (IOP) in children, according to a study published in Journal Français d’Ophtalmologie. Using this non contact method to obtain IOP measurements may present a better alternative to applanation tonometry, which can involve general anesthesia when performed on pediatric patients, the report suggests.
“Glaucoma is one of the main causes of visual impairment in children,” the study authors explain. “Ophthalmologists must diagnose it early enough to treat it effectively. Thus, measuring intraocular pressure (IOP) is essential. However, this IOP measurement
can be very challenging in children due to poor cooperation during the eye examination. When a congenital or juvenile glaucoma is suspected, eye examination under sedation or general anesthesia (GA) can be necessary to measure the IOP properly.”
Researchers included 72 children (eyes, 138; 46% girls, mean age, 2.87 years) who underwent an eye exam with general anesthesia between November 2019 and March 2020 in the prospective study. A total of 8 operators, which consisted of 5 ophthalmologists and 3 trainees, performed IOP measurements using applanation tonometry, followed by rebound tonometry 5 minutes later. The research team also obtained central pachymetry and axial length measurements.
The 2 devices showed high correlation (r, 0.8; P <.001) and moderate agreement (limits of agreement, −5.41-12.15 mm Hg; r, 0.5; P <.001), according to the report. Overall, rebound tonometry tended to overestimate by 3.37 mm Hg, which was weakly, but significantly correlated with mean IOP (r, 0.52; P =.006).
Correlation between the rebound tonometry and applanation tonometry devices was better among a subgroup of patients with glaucoma (r, 0.84; P <.001) compared with individuals without glaucoma (r, .67, P <.001). No correlation was noted with axial length and pachymetry values. Subgroup analyses revealed narrower boundaries of agreement among children younger than 3 years (−4.89-10.69) and participants without glaucoma (−3.75-10.48) and wider boundaries of agreement among patients with aphakia (−4.45-16.95), the report shows.
According to the researchers, the rebound tonometry device “is an easy-to-use tool to examine outpatient children. Its systematic use would reduce the need for general anesthesia in those children and would lead to significant changes in clinical practice.”
Study limitations include a failure to obtain double-blinded data collection and a single center design.
Chagny M, Stolowy N, Denis D, Sauvan L. Comparison of the iCare rebound tonometer and the Perkins applanation tonometer in children under general anesthesia. J Fr Ophtalmol. Published online May 18, 2023. doi:10.1016/j.jfo.2022.12.032