As studies investigating the Icare HOME arise, this can inform practitioners regarding the utility of the Icare HOME and its role in the management of glaucoma. 16 This device provides a recording for out-of-office variations in IOP through self-tonometry, as well as electronic documentation of these measurements. The Icare Home (TA022, Icare Oy, Vanda, Finland) is a relatively new rebound tonometer approved by the US Food and Drug Administration in March 2017, specifically designed for self IOP measurements at home. For this reason, rebound tonometry has been typically used for children and uncooperative patients in the past.
13 Additionally, they can be adapted into a small portable device that can be used with minimal training and do not require any topical anesthetic. 10 Rebound tonometers have shown to be comparable to GAT in measurement of IOP, 11, 12 and do not require regular calibration. Although various forms of ocular tonometry exist, rebound tonometry is particularly suited for this role. The ideal home tonometer would be reliable, user-friendly, portable, and convenient. With the advent of self-tonometry, 24-hour monitoring at home may become a viable option.
However, this is inconvenient, costly, and impractical for monitoring over longer periods. Twenty-four-hour monitoring of IOP of hospitalized patients may provide the most accurate measurements and can reveal higher peaks and wider fluctuation of IOP than those found during office visits. However, GAT is only performed in office settings, which prevents clinicians from monitoring IOP changes outside of the office and may make it difficult to assess a pharmaceutical or surgical treatment’s effectiveness. 9 Having said that, GAT continues to be the reference standard in IOP measurement, and all IOP measurement devices are universally calibrated to GAT. All other measurements are approximations of IOP through the cornea, sclera, or eyelid, including Goldmann applanation tonometry (GAT), which in fact underestimates true intracameral pressure. In its truest form, the most accurate measurement of IOP is done through an intracameral transducer. They found that 29% of patients with a progressive visual field loss had IOP peaks compared with 5% of patients with a stable visual field. 6, 7 Asrani et al evaluated diurnal IOP fluctuation with home self-tonometry in a group of open-angle glaucoma patients with apparently controlled office IOP.
Studies have shown that over 75% of single IOP measurements taken between 7am and 9pm tend to miss the highest point of a diurnal curve 5 and that a higher peak IOP may be an independent risk factor for progression of glaucoma. Diurnal variation in intraocular pressure is well recognized however, most decisions concerning glaucoma therapy are based on single IOP measurements captured at specific moments in office and therefore do not reflect IOP fluctuations over a 24-hour period. 1–3 As glaucoma is a leading cause of permanent blindness worldwide, 4 efforts to accurately monitor IOP changes over time are of paramount importance. Management of intraocular pressure (IOP) is the only readily modifiable risk factor known to slow the development and progression of glaucoma and visual disability. This article will also provide details and example cases for when the Icare HOME may be most clinically useful. The available literature has shown promising results in its accuracy of measuring IOP but suggests cautious usage in patients with central corneal thicknesses or IOP ranges that are outside of a certain range. The objective of this article is to review the existing literature surrounding the Icare HOME tonometer and its efficacy as a self-tonometer in comparison to GAT. Numerous studies have now compared the efficacy of the Icare HOME to that of GAT. IOP remains a major modifiable risk factor for glaucoma progression however, IOP measurements typically occur through single office measurements on Goldmann applanation tonometry (GAT) and do not always reveal the complete picture of patient’s IOP patterns and daily fluctuations, which are important for accurate diagnosis and evaluation. The Icare HOME (TA022, Icare Oy, Vanda, Finland) is rebound tonometer recently approved by the US Food and Drug Administration in March 2017 designed for self-measurement of intraocular pressure (IOP).