Rebound tonometry versus Goldmann tonometry in school children: feasibility and agreement of intraocular pressure measurements

Abstract

Tonometry is fundamental to routine ophthalmological evaluation, and Goldmann applanation tonometry (GAT) is the gold standard method. Several devices, including the Perkins tonometer, Tono-Pen, Pascal tonometer (dynamic contour), and non-contact tonometer, can provide reliable values in adults (1)(2)(3)(4) . However, in general practice, intraocular pressure (IOP) measurement can be difficult in children due to a lack of cooperation. ABSTRACTPurpose: High intraocular pressure (IOP) is an important risk factor for a variety of pediatric ophthalmic conditions. The purpose of this study is to evaluate the feasibility, length of examination, and corneal epithelial damage induced by rebound tonometry (RBT) versus Goldmann applanation tonometry (GAT) in school children. Methods: Healthy children (n=57) participated in a randomized, transversal study with IOP measurement by GAT followed by RBT (study arm 1) or RBT followed by GAT (study arm 2). The number of attempts to acquire a reliable IOP measurement and the length of the examination were quantified. Corneal epithelial damage induced by tonometry was evaluated. Bland-Altman analysis was performed to establish the level of agreement between the two techniques. Results: The IOP was measured in all children with at least one of the devices. In both study arms, more children failed to be examined with GAT than with RBT (26% vs. 4%, and 16% vs. 6%, p<0.001, in study arm 1 and 2, respectively). The length of examination was shorter for RBT than for GAT (67.81 s ± 35.20 s vs. 126.70 s ± 56.60 s; p<0.0001); IOP measurements with RBT in both study arms were higher than those with GAT (15.20 ± 2.74 mmHg vs. 13.25 ± 2.47 mmHg, p=0.0247 and 16.76 ± 3.99 mmHg vs. 13.92 ± 2.08 mmHg, p=0.003, respectively). No difference was observed between RBT and GAT regarding the corneal epithelial damage caused by tonometry. Conclusion: IOP measurement is feasible in a greater number of children with RBT, and the examination was faster than that for GAT. Compared with GAT, RBT tended to overestimate the IOP. None of the methods induced marked corneal epithelial defects.

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.…”

Posture-related fluctuations of intraocular pressure in healthy children with suspicion of glaucoma

“…When interpreting the IOP values with slightly increased pachymetry values, it must be considered that the values can be overestimated, especially in the case of IOP measurements with rebound tonometry. In a study with mean pachymetry of 558 ± 36 μm, values were approximately 2 mmHg higher with rebound tonometry than with Goldmann applanation tonometry in children [ 27 ]. It can therefore be assumed that the partly substantially increased IOP values are not solely attributable to rebound tonometry.…”

“…It can therefore be assumed that the partly substantially increased IOP values are not solely attributable to rebound tonometry. Furthermore, it must be taken into account that, especially in children, the measurement with Goldmann applanation tonometry is often not feasible; failure rates of up to 26% have been described [ 27 ].…”