Background and Objective:
Toxic anterior segment syndrome (TASS) is a sterile inflammatory syndrome with uncertain etiology, following cataract surgery. From October to December 2021 we observed a TASS cluster in our eye surgery department. To prevent further cases and understand the cause, a multi-level intervention was planned, based on environmental hygiene monitoring, personnel reeducation and a checklist-based data collection, investigating the major variables of the procedure.

Methods:
Both data from the checklist and medical records were gathered. A case-control statistical analysis, searching for significant correlations between variables and the subsequent onset of TASS cases, was carried out by calculating the binary logistic regression, using IBM SPSS on the data thus obtained. A p-value < 0.05 was accepted as significant.

Results:
All environmental monitoring, including surfaces and climatic variables such as air temperature, humidity, airflow and air exchange, fell within the range of the normative standards. Between cases (17) and controls, 131 records were consulted. The variables related to operators and patients showed no correlations with the onset of TASS, whilst, among the instrumental and procedural variables, the logistic regression highlighted the use of an enzymatic detergent in the sterilization procedure as the main risk factor (aOR= 9,47; 95% IC 1,06 – 84,28)

Conclusion:
Following this analysis, the enzymatic detergent was removed from the surgical tools sterilization process. One year later, no other cases of TASS were registered alongside no ocular infections following the procedure. The limited sample size and the need to find a quick solution for the cluster are the main issues of the study, since the multiple levels of intervention may have had overlapping effects. On the other hand, this can prove the effectiveness of a real-world, evidence-based, multi-level approach and give further evidence on this syndrome management.