Toxic anterior segment syndrome following penetrating keratoplasty

OBJECTIVES: To describe an outbreak of toxic anterior segment syndrome (TASS) following penetrating keratoplasty (PK) and to examine its possible causes. METHODS: Owing to a series of TASS following PK between June 6, 2007, and October 2, 2007, we reviewed the records of all patients who had undergone PK during that time. In addition to routine microbial tests on organ culture media, we looked for specific pathogens and endotoxins in all of the materials used for organ culture or PK. Furthermore, we analyzed all of the perioperative products and instrument processing. RESULTS: Of the 94 patients who underwent PK, we observed 24 cases of postoperative sterile keratitis. Causal research revealed that the accumulation of cleaning substances or heat-stable endotoxins on the surface of the routinely used guided trephine system was most likely responsible for the TASS. CONCLUSIONS: To our knowledge, this is the first report on TASS following PK. Suboptimal reprocessing of surgical instruments may be an important cause of TASS as in this series the TASS-like symptoms resolved after modified instrument-cleaning procedures. The standardization of protocols for processing reusable trephine systems might prevent outbreaks of TASS following PK.