Abstract
Purpose: :
The Goldmann applanation is the gold standard to measure intraocular pressure (IOP). Nonetheless several drawbacks remain: corneal contact exposes to an infectious risk, patient must usually be seated, measurements in children and pusillanimous patients are difficult and any modification of the corneal surface can alter the results. The mechanism of the ICARE tonometer (THIOLAT, Finland) is based on the measurement of the speed of the rebound of a small harmless disposable probe thrown onto the cornea without topic anaesthesia. This pilot study aims to evaluate the agreement between both methods.
Methods: :
Three trained physicians performed 314 consecutives measures on 29 glaucoma patients (primary open angle glaucoma) with both methods in a random order. Agreement between both tonometers was evaluated with the Bland and Altman method.
Results: :
IOP with ICARE were significantly higher (18+/–6 mmHg, from 6 to 54 mmHg, median 17mmHg) than with Goldmann applanation (16+/–6 mmHg, from 5 to 51 mmHg, median 15 mmHg, p<0.001). The Bland and Altman methods shows: a mean overestimation of 2 mmHg with ICARE. 95% of these measures are between –4 and +8 mmHg around Goldmann IOP. No variation of agreement in relation to the level of IOP is noted.
Conclusions: :
The new ICARE tonometer slightly overestimated IOP but remains clinically relevant in glaucoma patients. Considering the possible use of this tonometer in patients suffering from dystrophic cornea, in patient during post operative period, in children, and lying patients, this user–friendly tonometer may be an alternative method to the applanation tnonometer of Goldmann.
Keywords: intraocular pressure • optic disc • clinical (human) or epidemiologic studies: systems/equipment/techniques