Advice

Summary

Summary

Icare products are the only devices that currently use rebound tonometry to measure intraocular pressure. These help to assess the risk of developing glaucoma, and also to detect and monitor the condition. The 4 functionally similar Icare tonometers measure the deceleration and rebound time of a small, lightweight probe, which makes brief contact with the cornea. Evidence from 1 systematic review and meta‑analysis of studies published before 2010 showed that 52% (pooled value) of Icare intraocular pressure measurements were estimated to be within 2 mmHg of Goldmann applanation tonometer measurements. Five cross‑sectional studies (published after 2010) of mixed quality assessed the agreement between measurements obtained with Icare and those obtained with the Goldmann applanation tonometer, with variable results. The Icare tonometers cost between £1,595 and £3,695 excluding VAT. The disposable probes for each model cost between £50 and £100 for 100 probes.

Product summary and likely place in therapy

  • Icare tonometers measure intraocular pressure in adults and children of all ages. Intraocular pressure is measured to assess the risk of developing glaucoma, and also detect and monitor the condition.

  • They can be used in any setting and can either replace, or be used in addition to, existing tonometers.

Effectiveness and safety

  • The published evidence summarised in this briefing comes from 1 systematic review and meta‑analysis of studies published before 2010 (n=11,582 people; n=15,525 eyes); and 5 cross‑sectional studies of mixed quality published after 2010 (n=1025 people; n=1123 eyes). Only 1 of the studies was conducted in the UK. All 6 studies used the Goldmann applanation tonometer as a comparator.

  • The systematic review included 14 Icare studies. Evidence showed that 52% (pooled value) of Icare intraocular pressure measurements were estimated to be within 2 mmHg of the Goldmann applanation tonometer measurement.

  • In 1 cross‑sectional study (n=102 children), Icare overestimated intraocular pressure, whereas in a second study (n=99 people), it underestimated intraocular pressure. Two studies (n=327 and n=347 people) found agreement (using Bland–Altman analysis) between the 2 methods; however, there was less agreement at higher intraocular pressure values.

  • One study (n=150 people) found that measurements obtained with the Icare PRO were more accurate than those obtained with the Icare ONE.

Technical and patient factors

  • Icare tonometers are handheld, battery operated devices that use small, lightweight, single‑patient use probes.

  • Icare tonometers measure the deceleration and rebound time of the probe as it briefly touches the cornea, which it uses to calculate the intraocular pressure.

  • Icare tonometers can be used without local anaesthesia.

  • There are 4 models that use the same technology: Icare TA01i, Icare ic100, Icare PRO and Icare HOME (previously known as Icare ONE). Icare TA01i, Icare ic100 and Icare PRO are designed for use by optometrists or ophthalmologists and could be used in primary, secondary or tertiary care settings. Icare HOME is designed for use by patients or their carers in the home. Only healthcare professionals can view Icare HOME measurement results using Icare LINK software.

Cost and resource use

  • The capital cost of the Icare tonometers is £2,195 (Icare TA01i), £2,395 (Icare ic100), £3,695 (Icare PRO) and £1,595 (Icare HOME), excluding VAT.

  • The disposable probes cost £70 for 100 (Icare TA01i and Icare ic100), £50 for 100 (Icare PRO), and £50 for 50 (Icare HOME).

  • No published evidence on cost consequences and resource use was available.