The reuse of opthalmic minims : an unacceptable cross-infection risk?

Aims The instillation of a combined flourescein-anaesthetic eye drop is common practice in most ophthalmology clinics. Chauvin Pharmaceuticals produce unpreserved proxymethacaine 0.5% and flourescein 0.25% in a Minims ® vial (PFM) intended for single application only. Our aim was to determine whether the reuse of these eye drops for multiple applications has the potential for bacterial transmission. Methods Samples were collected from doctors in general outpatient clinics. Each sample constituted a blood agar plate inoculated with the initial drop of fluid from a PFM as a control. The vial was then used for multiple applications on consecutive patients. One of the last remaining drops was then inoculated onto an alternate marked site on the same plate to serve as the test sample. The samples were immediately transported to the Microbiology laboratory and incubated at 37°C for 48 h. The results were interpreted thereafter by a Microbiologist. Results A total of 41 samples were collected by eight Samplers. In all, 7/41(17%) samples showed growth of normal conjunctiva and lid flora on the test area. These were coagulase negative Staphylococci and Corynebacterium spp. Conclusions The reuse of single application of PFM should be questioned due to the potential risk of transmitting pathogens. A change to a single use only policy would result in a projected threefold increase in the annual budget for these drops.