Icare ONE Home Tonometry in Children With and Without Known Glaucoma.

Purpose: The Icare ONE (Finland Oy) rebound tonometer may have promise for home tonometry in children with glaucoma. The purpose of this study was: (1) to assess the feasibility of Icare ONE home tonometry in a small number of children with and without glaucoma and (2) to characterize diurnal intraocular pressure (IOP) variations in children with and without glaucoma.

Methods: Patients were recruited from Duke pediatric ophthalmology clinic. Parents underwent in-clinic training for Icare ONE tonometry. Parents were instructed to record the subject's IOP using Icare ONE at 6 time intervals daily for 10 sequential days.

Results: Eight normal subjects (16 eyes) and 10 subjects (10 eyes) with glaucoma were included. All parents successfully performed Icare ONE home tonometry. In-clinic Icare ONE IOP exceeded Goldmann applanation in both groups. Normal subjects (mean age, 11.8 y) had a mean daily IOP range of 4.8 ± 4.6 mm Hg for right eyes and 5.2 ± 1.7 mm Hg for left eyes, and demonstrated relative peaks in the morning and relative troughs in the evening. Subjects with glaucoma (mean age, 12.4 y) had a mean daily IOP range of 8.6 ± 8.2 mm Hg, and demonstrated an even distribution of relative peaks and troughs throughout the day.

Conclusions: Icare ONE home tonometry seems feasible in a small number of children. Normal eyes demonstrated smaller daily IOP ranges than glaucomatous eyes. Normal eyes were also more likely to show a relative early morning IOP peak and a late evening IOP trough. It is likely that the limited sampling in this study limits its generalizability to all children with glaucoma or to normal children.