Laboratory Study
Eye (2007) 21, 541–546. doi:10.1038/sj.eye.6702269; published online 3 February 2006
Tonometers and infectious risk: myth or reality? Efficacy of different disinfection regimens on tonometer tips
Competing Interest: The authors have no financial interest in any of the products mentioned
S Cillino1, A Casuccio1, G M Giammanco2, C Mammina2, D Morreale1, F Di Pace1 and G Lodato1
- 1Dipartimento di Neurologia, Oftalmologia, Otorinolaringoiatria e Psichiatria, Sezione di Oftalmologia, Università degli Studi di Palermo, Palermo, Italy
- 2Dipartimento di Igiene e Microbiologia, Università degli Studi di Palermo, Palermo, Italy
Correspondence: S Cillino, Dipartimento di Neurologia, Oftalmologia, Otorinolaringoiatria e Psichiatria, Sezione di Oftalmologia – Università degli Studi di Palermo, Via Liborio Giuffrè, no. 13, 90127 Palermo, Italy. Tel: +39 91 655 3904; Fax: +39 91 626 1438. E-mail: cillino@iol.it; casuccio@unipa.it
Received 29 April 2005; Accepted 16 December 2005; Published online 3 February 2006.
Abstract
Purpose
To evaluate the adequacy of common disinfection regimens for disposable tonometer tips and assess if disinfection of reusable prisms or the use of disposable tips is preferable.
Methods
We used disposable tonometer tips, using the same material and tip diameter of standard Goldmann tonometer prism. Strains of Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilisand Candida albicanswere tested according to the European standard guidelines for disinfectants test. Antimicrobial effectiveness of the following disinfection practices has been assessed: dry wipe, Minuten wipes (Alpro®), soaking in 3% hydrogen peroxide, 0.5% benzalkonium chloride, and 0.5% Pantasept® for 1, 5, and 15 min. All tests have been performed three times and all conditions tested in duplicate.
Results
Dry wiping and 1 min soak in 3% hydrogen peroxide were ineffective on all microrganisms. Minuten wipes, 1 min soak in 0.5% benzalkonium chloride or 3% hydrogen peroxide were ineffective on B. subtilis. 0.5% Pantasept® soak was effective in 1 min for all microrganisms tested, whereas 3% hydrogen peroxide and 0.5% benzalkonium chloride soaks were effective when performed for at least 5 min. B. subtiliswas the most resistant organism to disinfectant regimes at 1 min time.
Conclusions
Results of our study demonstrate a relative disinfection efficacy for the different evaluated regimens, provided that correct exposure times are adopted for the chosen disinfectants, a condition difficult to ensure in a busy clinic setting. We conclude that disposable prism tonometry provides a safe alternative to Goldmann tonometry.
Keywords:
disposable tonometer prisms, ophthalmic device disinfection, cross-infection ophthalmic transmission
