Needle Contamination in the Setting of Intravitreal Injections

In Brief Background/Purpose: To evaluate the risk of intravitreal needle contamination through speaking versus breathing in an office setting. Methods: This was a prospective sampling assay. Participants held a sterile 30-gauge half-inch needle 25 cm from their mouth for 30 seconds under 2 conditions: 1) while speaking and 2) while breathing silently. Needles were then cultured and assayed after 6 days of incubation. Absolute colony-forming units were compared between conditions and against control sterile needles and oral swab cultures. Results: Ten physicians were sampled with 15 samples per physician. Participants grew an average of 0.21 colonies (median = 1 CFU) from their talking samples and 0.07 colonies (median = 1 CFU) from their silent breathing samples. Oral swab plates grew an average of 373.4 colonies. None of the control needle plates grew colony-forming units. A nominal regression analysis showed no significant difference between talking and silent samples (P = 0.457). Conclusion: No significant difference in needle contamination was found between talking and breathing. Compared with oral swab plates, a significant difference exists between the amount of flora colonizing the oropharynx and that which was found on the needle cultures (P < 0.0001). These findings suggest that speaking versus remaining silent makes no difference in regard to needle contamination with oral flora during intravitreal injection. No significant difference in needle contamination was found between talking and breathing. Compared with oral swab plates, a significant difference exists between the amount of flora colonizing the oropharynx and that which was found on the needle cultures (P < 0.0001). These findings suggest that speaking versus remaining silent makes no difference in regard to needle contamination with oral flora during intravitreal injection.