Causative Pathogens in Endophthalmitis after Intravitreal Injection of Anti-vascular Endothelial Growth Factor Agents

Intravitreal injection of anti-vascular endothelial growth factor is currently the preferred treatment for several posterior segment diseases, including age-related macular degeneration and diabetic retinopathy, as well as macular edema and retinal vein occlusion. As an invasive procedure it involves risks. The most significant risk is infectious endophthalmitis, a sight-threatening and even a globe-threatening acute fulminant condition. Most common pathogens include Streptococcus and Staphylococcus species, surprisingly originating from the patient's, surgeon's, or nurse's mouth. Infectious endophthalmitis may have devastating and irreversible effect, with Streptococcus-induced cases having the worst visual outcome. It is therefore crucial for clinicians to promptly recognize and treat such conditions, and, far more important, to put in place protective and preventive measures against this rare, but sight-threatening complication. To that end, this paper describes the most common pathogens causing endophthalmitis after IVI of anti-VEGF, and defines their source, to aid the physician in developing strategies to prevent this catastrophic infection.