The impact of short-term topical gatifloxacin and moxifloxacin on bacterial injection after hypodermic needle passage through human conjunctiva

Study of the Acute Effects of Povidone-Iodine on Conjunctival Bacterial Flora

PURPOSE

The purpose of this laboratory study was to assess the effect of povidone-iodine (PI) use topically on the conjunctiva in regard to needle bore contamination and to compare these results with our previous findings from an evaluation of bacterial contamination following gatifloxacin and moxifloxacin administration.

METHODS

We performed 100 conjunctival 27-gauge needle penetrations of both eyes of 13 fresh cadavers. Eyes were then soaked in 10% PI, after which conjunctiva was again penetrated 100 times. After conjunctival penetration, the needles were irrigated, and the irrigant was assessed for bacterial growth. Results were compared with previous work assessing fluoroquinolone effectiveness through the same model.

RESULTS

We observed a 28% (P = 0.003) decrease in bacterial growth and 40% (P < 0.0001) decrease in colony counts after PI placement. Differences between the effect of PI versus moxifloxacin and gatifloxacin were not statistically significant.

CONCLUSIONS

There is a greater decrease in bacterial load after treatment with PI for surface cultures than for cultures obtained through a needle bore passed through the conjunctiva. PI is a superior approach to topical antibiotics to decrease conjunctival bacterial load.