Minimising the risk of prion transmission by contact tonometry
- 1Institute of Ophthalmology, Department of Pathology, Bath Street, London EC1V 9EL, UK
- 2Moorfields Eye Hospital, City Road, London EC1V 2PD, UK
- 3Department of Optometry and Visual Science, City University, Northampton Square, London EC1V 0HB, UK
- Correspondence to: Professor R J Buckley 57A Wimpole Street, London W1G 8YP, UK; RJBcityaol.com
- Accepted 3 March 2003
Abstract
Aims: The unknown prevalence of variant Creutzfeldt-Jakob disease (vCJD) in the UK population has led to fears of horizontal transmission through routine medical procedures. The potential risk of transmission via contact tonometry was examined.
Methods: The total amount of protein carried over by tonometer tips after applanation of patients was assessed.
Results: Tonometer tips had an inherent ability to carry proteinaceous material. There was a large variability in the load carried over between individual patients. Rinsing tonometer tips in water reduced protein carryover. Wiping the tonometer tips also reduced carriage, though less dramatically.
Conclusion: There is a small theoretical risk of transmission of vCJD by contact tonometry through reuse, but this should be reduced if the prisms are washed and wiped. In the light of these findings a protocol for the management of reusable tonometer prisms is recommended.







