Clinical Study

Eye (2008) 22, 1029–1033; doi:10.1038/sj.eye.6702831; published online 20 April 2007

Tonometer disinfection practice in the United Kingdom: A national survey

Financial or proprietary interest: nil

Financial Support: nil

R J Hillier1 and N Kumar1

1Ophthalmology Department, Aintree University Hospitals NHS Foundation Trust, Walton Hospital, Liverpool, UK

Correspondence: RJ Hillier, SpR in Ophthalmology, Manchester Royal Eye Hospital, Oxford Road, Manchester M13 9WH, UK. Tel: +44 07811 190588; Fax: +44 0161 276 5555; E-mail:

Received 2 October 2006; Revised 16 March 2007; Accepted 16 March 2007; Published online 20 April 2007.





To assess current tonometer disinfection practice in the UK, and compare with published recommendations.



Every ophthalmology unit with training recognition in the UK was contacted (n=155). A senior nurse at each institution completed a telephone questionnaire regarding local tonometer disinfection practice.



The response rate was 100%. Thirty-five units (23%) reported exclusive use of disposable tonometer heads and were excluded from further analysis. One hundred and twenty units (77%) used either reusable or a combination of reusable and disposable tonometer heads. Where reusable heads were used, 80 units (67%) immersed them in a chlorine-based solution such as sodium hypochlorite or sodium dichloroisocyanurate. Others used isopropyl alcohol (18 units), hydrogen peroxide (12 units), chloramine (5 units), chlorhexidine (4 units) and peracetic acid (1 unit). Where a chlorine-based agent was used, the concentration of available chlorine ranged from 125 to 30000p.p.m., with 50 units (63%) using a concentration of less than 5000p.p.m. (i.e., inadequate based on published recommendations). Where the tonometer head was immersed in disinfectant between patients (n=101), 29 units (29%) provided just one tonometer head per practitioner, making adequate soak time between patients unlikely. Every unit replenished the disinfectant at least daily, deemed sufficient for most agents. However, hydrogen peroxide solutions should be replenished twice daily, which did not take place in nine units.



This survey reveals disparity between current tonometer disinfection practice and published international recommendations, with some institutions using practices that may render patients susceptible to transmissible infection.


disinfection, tonometry, glaucoma