The Impact of Short-Term Topical Gatifloxacin and Moxifloxacin on Bacterial Injection After Hypodermic Needle Passage Through Human Conjunctiva

Abstract

To determine the bacterial contamination rate of a 27-gauge needle bore during conjunctival penetration in donor eye bank eyes and the effect of short-term use of topical 0.3% gatifloxacin and 0.5% moxifloxacin. One hundred consecutive human donors had 10 conjunctival penetrations per 10 syringes per eye before antibiotic placement; this was repeated 15 min after antibiotic use. Samples were cultured by expressing 0.3 mL of saline through the needle. Positive cultures were speciated. There were 1,033 positive cultures (25.8% of all cultures); 568 (28.4%) pre-antibiotics, 249 (24.9%) after gatifloxacin (P=0.04, compared to the pre-antibiotic rate), and 216 (21.6%) after moxifloxacin (P<0.001). The most common organism was Staphylococcus epidermidis [334 positive cultures (8.4%)]. No antibiotic effect was seen on this or other organisms except S. aureus [4.6% pre-antibiotic, 2.8% after gatifloxacin (P=0.02), and 1.8% after moxifloxacin (P<0.001)] and other Staphylococcus species [5.3% pre-antibiotic, 3.6% after gatifloxacin (P=0.04), and 3.2% after moxifloxacin (P=0.01)]. Transconjunctival penetration often results in needle bore contamination; bacteria are included in an injected solution. Fifteen minutes of exposure to 2 topical antibiotics had a minimal effect on bacterial contamination and no significant effect on many common pathogens.