Home assessment of diurnal intraocular pressure in healthy children using the Icare rebound tonometer

Background Although intraocular pressure (IOP) is known to vary with the circadian cycle in nonglaucomatous and glaucomatous eyes of adults, the clinical assessment of IOP often relies on periodic measurements obtained at office visits during daytime hours. Little has been reported on diurnal IOP patterns in healthy children. The purpose of this study was to evaluate diurnal IOP in normal eyes of healthy children with the Icare rebound tonometer and when recorded by a parent at home. Methods This was a prospective study of IOP in normal eyes of healthy children. Children were recruited from a pediatric eye clinic. A parent was instructed on the use of the Icare rebound tonometer by a study physician and demonstrated proficiency its use in the clinic, at which time a masked IOP reading was also made with Goldmann applanation by a different study clinician. Home IOPs were then obtained and recorded 6 times daily at 2- to 3-hours intervals during 2 consecutive days by a parent. Results A total of 22 normal eyes (of 11 children) were included. We found that children without glaucoma demonstrate mean diurnal IOP fluctuation of 4-6 mm Hg, with similar IOP between right and left eyes, fair repeatability between consecutive days, and a tendency for higher early morning and lower late evening IOP. Conclusions Healthy children without glaucoma demonstrate some diurnal fluctuation in IOP, comparable with that reported in nonglaucomatous eyes of adults. This information should prove as comparative for assessment of IOP fluctuation in children with known or suspected glaucoma.