Related Experiment Video
Updated: Dec 3, 2025
Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis
Published on: February 6, 2021
Bacterial Dispersion Associated With Various Patient Face Mask Designs During Simulated Intravitreal Injections
Samir N Patel1, Raziyeh Mahmoudzadeh1, Mirataollah Salabati1
1Wills Eye Hospital, Mid Atlantic Retina, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Purpose:
We sought to investigate bacterial dispersion with patient face mask use during simulated intravitreal injections.
Design:
Prospective cross-sectional study.
Methods:
Fifteen healthy subjects were recruited for this single-center study. Each participant was instructed not to speak for 2 minutes, simulating a "no-talking" policy, while in an ophthalmic examination chair with an blood agar plate secured to the forehead and wearing various face masks (no mask, loose fitting surgical mask, tight-fitting surgical mask without tape, tight-fitting surgical mask with adhesive tape securing the superior portion of the mask, N95 mask, and cloth mask). Each scenario was then repeated while reading a 2-minute script, simulating a talking patient. The primary outcome measures were the number of colony-forming units (CFUs) and microbial species.
Results:
During the "no-talking" scenario, subjects wearing a tight-fitting surgical mask with tape developed fewer CFUs compared with subjects wearing the same mask without tape (difference 0.93 CFUs [95% confidence interval 0.32-1.55]; P = .003). During the speech scenarios, subjects wearing a tight-fitting surgical mask with tape had significantly fewer CFUs compared with subjects without a face mask (difference 1.07 CFUs; P = .001), subjects with a loose face mask (difference 0.67 CFUs; P = .034), and subjects with a tight face mask without tape (difference 1.13 CFUs; P < .001). There was no difference between those with a tight-fitting surgical mask with tape and an N95 mask in the "no-talking" (P > .99) and "speech" (P = .831) scenarios. No oral flora were isolated in "no-talking" scenarios but were isolated in 8 of 75 (11%) cultures in speech scenarios (P = .02).
Conclusion:
The addition of tape to the superior portion of a patient's face mask reduced bacterial dispersion during simulated intravitreal injections and had no difference in bacterial dispersion compared with wearing N95 masks.
Insights
Adding tape to surgical masks significantly reduced bacterial dispersion during simulated intravitreal injections. This method proved as effective as N95 masks in preventing germ spread, enhancing patient safety.
Area of Science:
- Ophthalmology
- Infectious Disease Control
- Medical Microbiology
Background:
- Intravitreal injections require strict aseptic techniques to prevent microbial contamination.
- Patient-generated aerosols and respiratory droplets can potentially disperse bacteria during ophthalmic procedures.
Purpose of the Study:
- To evaluate the efficacy of different patient face mask types in reducing bacterial dispersion during simulated intravitreal injections.
- To compare the effectiveness of enhanced surgical masks with N95 respirators.
Main Methods:
- A prospective cross-sectional study involving 15 healthy subjects.
- Simulated intravitreal injection scenarios with and without patient speech.
- Bacterial dispersion measured using colony-forming units (CFUs) on agar plates placed on the forehead.
- Testing included no mask, loose surgical, tight surgical (with/without tape), N95, and cloth masks.
Main Results:
- Tight-fitting surgical masks with tape significantly reduced CFUs compared to those without tape during both no-talking and speech scenarios.
- Tight-fitting surgical masks with tape showed comparable bacterial dispersion reduction to N95 masks.
- Oral flora was isolated in 11% of cultures during speech scenarios but not during no-talking scenarios.
Conclusions:
- Taping the superior portion of surgical masks effectively minimizes bacterial dispersion during simulated intravitreal injections.
- This simple modification offers a comparable level of bacterial containment to N95 masks.
- Face mask use, particularly enhanced surgical masks, is crucial for reducing microbial contamination risk in ophthalmic procedures.
