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.