Mobile Laminar Airflow for Intravitreal Injections: Reducing Microbial Load at the Instrument Field

Background/Objectives: Intravitreal injections (IVIs) are increasingly performed in outpatient settings, raising concerns regarding how to guarantee operating-theatre-level environmental safety. Mobile laminar airflow (LAF) units may create an ultraclean instrument field, but microbiological evidence from real-world IVI clinics is limited. Methods: We performed environmental monitoring during three IVI sessions, each including approximately 20 injections per session, in an outpatient procedure room equipped with a mobile LAF device (Operio Toul Mobile). Airborne microbial contamination was measured with a SAS Super 100 impactor (1 m³ per sample) at two locations, the procedure-room air and the LAF field, across seven predefined time points (T_-1to T₅). Surface contamination of the instrument-covering drape was assessed at mid- and end-session using 24 cm² contact plates on four culture media. Colonies were expressed as CFU/m³ or CFU/24 cm² and analysed using a two-way repeated-measures ANOVA (location × time), with Holm-adjusted within-session paired post hoc comparisons at each time point. Results: During LAF operation (T₀-T₄), mean airborne load was 89.8 ± 10.8 CFU/m³ in room air versus 10.9 ± 4.6 CFU/m³ under LAF, corresponding to an 87.9% mean reduction (Holm-adjusted p < 0.01). At T_-1 and T₅ (LAF off), counts were not significantly different between locations. Airborne microbial species consisted mainly of skin/oral commensals; no obligate pathogens were detected. All 24 drape samples showed 0 CFU. Conclusions: In this high-throughput outpatient IVI clinic, the mobile LAF device maintained a stable ultraclean microenvironment at the instrument field despite moderate background room contamination, supporting its use as an adjunct to standard aseptic measures, without the need to change the covering drape during the session.