Purpose: To compare the contamination rate between 27-gauge and 30-guage needles used for intravitreal injection (IVT).
Methods: Patients undergoing IVT injections were enrolled prospectively. Injections were performed with 27- or 30-gauge needles. All needle tips were collected and placed in brain-heart infusion broth. The contamination rates of needles were compared.
Results: A total of 109 patients participated in the study and a total of 126 IVT injections were performed. Injections were performed by 27-gauge (49%) and 30-gauge (51%) needle. No patient developed endophthalmitis. The overall contamination rate of the used needles were 13% for 27-guage and 29% for 30-guage (p = 0.022). However, this difference was nonsignificant after Bonferroni's correction was applied. The most common bacteria isolated from the used needles are coagulase-negative Staphylococcus (CNS).
Conclusion: The results suggest that the needle bore size seems not to be a risk factor for contamination during IVT injection.