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Intraocular pressure (IOP) measurement ‐ an important part of the examination of infants and children with known or suspected glaucoma ‐ is nonetheless challenging to obtain in the office setting. The ICare rebound tonometer does not require the use of topical anesthetic to obtain measurements of IOP, and has proven reproducible and similar to Goldmann applanation in adults and in cooperative children. Lundvall et al. (131) present results of a prospective study using ICare tonometry to measure IOP in healthy, white infants and toddlers in a child welfare center and eye clinic in Stockholm, Sweden. The purpose of this study was to evaluate the tolerability of ICare tonometry and to establish normative IOP values in healthy children aged 1-36 months. The authors enrolled 46 subjects, and took the mean value of three consecutive single IOP readings (rather than the customary six reading required by the ICare instrument to determine a reliability level for the overall measured IOP) in one eye of each child; ten cooperative children were then measured again a few minutes later by a second examiner (masked to the results of the first examiner). The subject was excluded if the three ICare readings differed by more than 3 mmHg from one another.
ICare tonometry was not possible in 6/49 infants; one additional infant had readings with more than 3 mmHg spread; hence ICare tonometry was possible in 39/46 (85%) subjects, with median IOP 10 mmHg (range 7.3-17.0). In 9/10 infants (median age 8 months) the IOP measured by two different examiners was very similar (mean overall difference 0.77 mmHg). ICare IOP did not correlate with infant age in this study.
Limitations include small numbers, narrow age range, single ethnicity, lack of corneal thickness data, and inclusion of healthy eyes only. Additionally, 13% of tested normal infants were not cooperative despite the modification of the recommended Icare tonometry protocol (to include only three isolated IOP readings rather than six), Limitations notwithstanding, this study confirms that Icare tonometry is well tolerated in most infants, and provides normative IOP values for the unanesthetized healthy infant's eye.