Abstract
Purpose: :
To describe the study design and present the interim results of a prospective, multicenter study evaluating the culture-positivity of needles used for intravitreal injections in patients.
Methods: :
Patients undergoing intravitreal injection of ranibizumab or off-label bevacizumab at seven centers were enrolled in a prospective fashion. Following standard povidone-iodine preparation of the ocular surface, conjunctival cultures were obtained. The intravitreal injection was then administered, after which the needle was separated from the syringe and collected in a culture tube. A control needle exposed to room air was also sent for culture. To achieve adequate statistical power, an enrollment goal of 100 patients was established. The rate of culture-positive needles was to be calculated from this group as an indicator of the likelihood that the injection needle itself serves as a vehicle for bacterial entry into the eye.
Results: :
Enrollment began in March 2008. As of December 2008, 66 patients were enrolled. 11% of conjunctival swabs were positive on blood agar plates. 17 of 66 used needles yielded positive cultures (26%). Of the unused control needles, 4 of 66 were positive (6%). There were no cases of endophthalmitis among study patients.
Conclusions: :
Interim results suggest a higher than expected number of used needles yielding positive bacterial cultures. Due to the low incidence of endophthalmitis with intravitreal injections, decisions regarding techniques for antisepsis and antibiotic prophylaxis may need to be informed by surrogate endpoints such as needle contamination rates.
Keywords: endophthalmitis • injection