Purpose: To evaluate the safety of bilateral same-day intravitreal injections using a single vial and to introduce a molecular surveillance system to screen bacterial drug contamination using eubacterial polymerase chain reaction (PCR).
Methods: Retrospective review of the medical records of 135 patients who received 574 bilateral same-day intravitreal injections for various retinal diseases in 2 tertiary referral hospitals between January 2008 and March 2010 was performed. Data were obtained regarding the diagnosis, kinds of drugs injected, postinjection complications, and the result of molecular bacterial screening of the injected drugs. Drugs for bilateral intravitreal injections were drawn from a single vial and injected using separate syringes or needles. Molecular bacterial screening was performed using the remaining drug in the syringe by 16S ribosomal DNA real-time PCR.
Results: A total of 574 injections (384 bevacizumab, 154 ranibizumab, and 36 triamcinolone) were administered on bilateral eyes of 135 patients. There were no complications, including endophthalmitis, uveitis, retinal tear, or retinal detachment. Of the 278 injections screened for bacterial contamination using eubacterial PCR, no cases (0%) showed drug contamination by bacteria. The sensitivity of eubacterial PCR for molecular bacterial screening was 10 colony-forming units (CFUs)/mL or lower.
Conclusion: Bilateral same-day intravitreal injections drawn from a single vial using separate syringes or needles are well tolerated by patients, and its safety profile may be equivalent to unilateral injections. The bacterial molecular surveillance system using eubacterial PCR demonstrated the safety of bilateral same-day intravitreal injections and may be used for safety surveillance and for timely intervention of possible drug-related endophthalmitis.