Bacterial contamination of needles used for intravitreal injections: a prospective, multicenter study.

PURPOSE: To determine the incidence of bacterial contamination of needles used for intravitreal injections. METHODS: Patients undergoing intravitreal injections were enrolled prospectively. No pre-injection antibiotics were administered. Following povidone-iodine irrigation, conjunctival cultures were taken and the injection was performed. The needle was cultured. A dry control needle was exposed to the surgical field and cultured. RESULTS: No patients developed endophthalmitis. Eighteen injection needles (18%) yielded positive bacterial growth. The most commonly encountered organisms were Propionibacterium acnes (n = 8) and Staphylococcus epidermidis (n = 6). Four control needles showed positive growth, in 2 cases with the same organism as a matching positive used needle. The difference between contamination rates of used and control needles was significant (p = .002, McNemar's test). CONCLUSIONS: Bacterial contaminants are present on a substantial proportion of needles. Since the needle contacts both the ocular surface and the vitreous, it is possible that inoculation of the vitreous cavity occurs in such cases.

Duke Scholars

Author Prithvi Mruthyunjaya Ophthalmology, Vitreoretinal Diseases & Surgery