Self-tonometry to manage patients with glaucoma and apparently controlled intraocular pressure
J. T. Wilensky, D. K. Gieser, M. T. Mori, P. W. Langenberg and R. C. Zeimer
We tested a self-tonometer than can be used by the patient alone to monitor
intraocular pressure (IOP) in a normal environment. The instrument is
safely and easily used after training. Normal subjects and patients with
glaucoma who had an IOP of 22 mm Hg or less at three consecutive visits
were referred for diurnal monitoring. After successful training, they
received a self-tonometer and instructions to obtain five measurements
daily between awakening and bedtime for three to six days. More than half
the patients had one or more readings above 22 mm Hg. About half of the IOP
peaks occurred at times outside of normal office hours. Interestingly, more
elevated IOP readings were recorded in patients with suspected or
documented progression of glaucomatous damage than in patients thought to
be stable or in normal subjects. In eyes that have already sustained
glaucomatous damage, the progression may be explained by the presence of
previously undocumented IOP peaks. Valuable additional clinical information
can be gained by diurnal IOP monitoring, and the self-tonometer is a
practical tool for its measurement.
