DLK Associated with Table-top Autoclave Biofilms: Case Series and Review.

To report a diffuse lamellar keratitis (DLK) cluster attributed to autoclave reservoir biofilm and to review the risk and prevention of DLK and toxic anterior segment syndrome (TASS) caused by such biofilmsSETTING: Refractive Surgery Center, University of California, BerkeleyDESIGN: Observational case control study and review of literaturePARTICIPANTS: Patients undergoing LASIK by the same surgeon at the surgery centerMETHODS: Eyes were evaluated for DLK following LASIK over a 5 year period. Multiple changes in surgical and operating room protocols were prompted by a cluster of DLK cases. The autoclave reservoir chamber wall was cultured for microbial contamination. MEDLINE database was utilized to identify relevant past publications.Incidence of post-LASIK DLK; Microbial culture results of autoclave reservoir biofilm.From January 7, 2010 to December 18, 2014, 1,115 eyes received LASIK. Between September 2, 2010 and June 11, 2012, 147 eyes of 395 LASIK cases developed DLK (37.2 %). Systematic modifications in surgical protocols were unsuccessful in ending the prolonged cluster of DLK cases until the StatIM 2000 autoclave was replaced with a new StatIM autoclave and a reservoir sterilization and surveillance protocol implemented. Over the subsequent 30 months, DLK incidence was reduced to 2.2 % (14 DLK cases from 632 total LASIK cases, p < 0.0001). The retired autoclave reservoir chamber wall cultures grew Pseudomonas aeruginosa and Burkholderia cepacia complex.Fluid reservoirs of table-top steam autoclaves can readily develop polymicrobial biofilms harboring microbial pathogens, whose inert molecular byproducts can cause DLK and TASS when introduced to the eye by surgical instruments. Stringent reservoir cleaning and maintenance may significantly reduce this risk by preventing and removing these biofilms.