Meta-analysis of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents: causative organisms and possible prevention strategies.

PURPOSE: To report the rates of endophthalmitis and the spectrum of causative organisms after intravitreal injection of anti-vascular endothelial growth factor agents and possible prevention strategies.
METHODS: Meta-analysis of the U.S. literature from 2005 to 2009 reporting endophthalmitis bacterial isolates after intravitreal injection of anti-vascular endothelial growth factor agents and comparison with reports of endophthalmitis bacterial isolates after intraocular surgery in the United States. RESULT: Endophthalmitis after intravitreal injection occurred in 52 of 105,536 injections (0.049%) (95% confidence interval [CI], 0.038-0.065%). Among 50 cases of endophthalmitis with bacterial culture isolates, 24 (48.0% [95% CI, 34.8-61.5%]) were culture negative and 26 (52% [95% CI, 38.5-65.2%]) were culture positive. Among the 26 culture-positive isolates, causative organisms were coagulase-negative Staphylococcus in 17 cases (65.4% [95% CI, 46.0-80.6%]), Streptococcus species in 8 cases (30.8% [95% CI, 16.5-50.2%]), and Bacillus cereus in 1 case (3.8% [95% CI, 0.9-19.0%]). Streptococcus species were significantly more frequent after intravitreal injection than after intraocular surgery in the Endophthalmitis Vitrectomy Study (29 of 226 isolates, 9.0% [95% CI, 6.3-12.6%], P = 0.005), a report on clear corneal cataract surgery endophthalmitis (6 of 73 isolates, 8.2% [95% CI, 3.9-16.8%], P = 0.022), and a report on postvitrectomy endophthalmitis with no cases of Streptococcus species.
CONCLUSION: Streptococcal isolates are approximately three times more frequent after intravitreal anti-vascular endothelial growth factor injection than after intraocular surgery. Strategies to consider minimizing oropharyngeal droplet transmission may include avoiding talking, coughing, and sneezing or wearing surgical masks.