Sterile hypopyon secondary to ultrasonic cleaning solution

During a 20-week period, 21 cases of sterile hypopyon occurred 24 hours after uncomplicated extracapsular cataract extraction and in-the-bag posterior chamber intraocular lens implantation at the Valley Eye Institute. While all cases responded to steroid treatment and exhibited no residual ocular effects, the cause of the hypopyon remained a mystery despite an on-going reevaluation of the surgical procedure and sterilization techniques. Several suspected causes were investigated and eliminated. It was clinically determined that surgical instruments placed in older ultrasonic cleaning solution caused the hypopyons. Further analysis at the Center for Intraocular Research at the University of Utah revealed that the instruments were contaminated by a heat-stable endotoxin that remained on the instruments through the autoclaving process. Surgeons currently using ultrasonic instrument cleaners should be aware that, with some models, following the manufacturer's recommended fluid changing procedures could result in endotoxic contamination of surgical instruments which could, in turn, cause severe inflammatory reactions in the immediate postoperative period.