An investigation into the bacterial contamination of goniolenses in use in clinical practice

Abstract

Objectives To report the incidence and evaluate the clinical significance of goniolens bacterial contamination in clinical use in dogs with three different usage protocols and one with an added cleaning protocol. Animals Studied and Methods Three groups of twenty dogs undergoing gonioscopy at a private practice in the UK had the goniolenses swabbed for bacteriology culture and identification prior to placement on the cornea. Three protocols of lens use, with 2 different types of goniolens, were studied. One protocol was then repeated with 21 dogs with a lens cleaning protocol prior to storage. Results Low levels of bacterial contamination were found in all 3 initial groups (10-15%). No correlation was found between usage protocol used and rate of contamination and no correlation was found between length of storage between use and contamination. All bacteria cultured were considered naturally occurring commensals for the canine eye and environment. The group with a cleaning protocol had a 4.7% contamination rate. This was not statistically different from the non-cleaning groups. Conclusions The rate of bacterial contamination of goniolenses in clinical practice is low and the bacterial contaminants consist of commensal bacteria, unlikely to be of detriment to the eye. Minimal contamination of the goniolenses was found and this did not appear to be of clinical significance. The introduction of a simple cleaning protocol did not produce a statistically significant reduction in bacterial contamination.

An assessment of bacterial contamination of indirect ophthalmoscopes and condensing lenses used in clinical practice: A multi‐center study

“…No significant differences existed between centers and the number of isolates sampled. Baseline bacterial contamination was much greater in this study than that previously reported for other diagnostic equipment used in veterinary ophthalmology (goniolenses 11.7% 15 and slit lamps 58.7% 14 ). Increased clinician contact points on the indirect ophthalmoscope (forehead skin and hair) may have contributed to increased contamination.…”

“…No significant differences existed between centers and the number of isolates sampled. Baseline bacterial contamination was much greater in this study than that previously reported for other diagnostic equipment used in veterinary ophthalmology (goniolenses 11.7% 15 T A B L E 2 Bacteria isolated from baseline swabs (TO) prior to the introduction of cleaning protocol (centers 1 and 2 had 4 swabs per sampling site and center 3 had 2 swabs per sampling site). and slit lamps 14 ).…”

“…Hands are a recognized and common vector for transmission 13 . Two studies revealed that 58% of handheld slit‐lamps, 14 and 11.7% of unwashed goniolenses 15 demonstrated bacterial contamination. To the author's knowledge, neither the indirect ophthalmoscope nor condensing lens has been screened for bacterial contamination in a veterinary health care setting.…”