Bacterial Contamination of Needles Used for Intravitreal Injections: A Prospective, Multicenter Study

Abstract

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.

KEYWORDS::

• contamination
• endophthalmitis
• intravitreal injection
• needle

ACKNOWLEDGMENTS

The results of this study were presented at the Retina Congress 2009, New York, NY, October 2009.

The authors thank Vicky Cevallos (microbiology consultation) and Travis Porco, PhD (statistical consultation) at the Francis I. Proctor Foundation for Research in Ophthalmology, University of California, San Francisco.

Declaration of interest: Funding/support: Connect Network. Two authors, S. M. Hariprasad and M. B. Ober, participated in the design and conduct of this research and are members of the Connect Network Board of Directors. The Connect Network is a 501(c)(3) nonprofit organization that has received financial support from Alcon, Allergan, Eyetech, Genentech, and Santen. These funding sources had no role in the design or conduct of this research.

Financial disclosures:

• Jay M. Stewart: none

• Sunil K. Srivastava: Consultant (Novartis, Bausch and Lomb)

• Anne E. Fung: Consultant (Genentech, Santen); lecture fees (Genentech); Financial support (Genentech)

• Tamer H. Mahmoud: none

• David G. Telander: Consultant (OIS/Eyetech, Genentech); lecture fees (Genentech, Allergan)

• Seenu M. Hariprasad: Consultant (Alcon, OD-OS, Ocular Therapeutix, Pfizer, Glaxo SmithKline); speaker’s bureau (Genentech, Alcon, Allergan)

• Michael D. Ober: lecture fees (Alcon); financial support (Connect Network)

• Prithvi Mruthyunjaya: none