However, cultures yielded Streptococcus organisms 30.8% of the time (8 of 26), which Dr. McCannel said is "3- or 4-fold higher" than the incidence reported in the literature for acute postoperative endophthalmitis. The postoperative incidence of streptococcal endophthalmitis ranges from 0% after vitrectomy to 8.2% to 9% after cataract surgery, he reported.
Likely Source of Infection:
He found several studies in the anesthesia literature reporting streptococcal meningitis after dural puncture, a procedure that, according to Dr. McCannel, has a working distance between physician and patient similar to that of IVI. Analysis found that the causative organisms in most of those cases came from the treating physician's oral flora, which was aerosolized during talking.
Consequently, the Centers for Disease Control and Prevention in Atlanta, Georgia, recommended in 2007 that spinal procedure operators wear a surgical mask during the procedure (MMWR Morb Mortal Wkly Rep.2010;59:65-69).
Implications of the Study
- Endophthalmitis is rare occurrence after intravitreal injections, which are commonly performed for age-related macular degeneration, diabetic macular edema, retinal vein occlusion and other conditions.
- Streptococcal infections are more common after intravitreal injections compared to other intraocular procedures. Mouth is an important reservoir of streptococci.
- Talking, coughing and sneezing should be minimized after the lid speculum has been placed to open the eye prior to administration of intravitreal injections.
- If a surgeon needs to talk to the patient while administering intravitreal injections, he should turn his face away from the surgical field.
- Although wearing a mask appears to be a good idea, it is not commonly done, including by the author of the study mentioned.
- A surgeon should, however, be aware of the possibility of contamination of surgical field by talking, and should take steps to minimize it.