Postop Endophthalmitis Traced to Contaminated Trypan Blue

Brian Hoyle

October 22, 2011

October 22, 2011 (Orlando, Florida) — A large outbreak of postoperative endophthalmitis caused by multidrug-resistant Pseudomonas aeruginosa after phacoemulsification was traced to contaminated trypan blue solutions.

The outbreak was described in a poster by researchers from Kaiser Permanente in Modesto, California, here at the American Academy of Ophthalmology 2011 Annual Meeting.

Although the involvement of P aeruginosa has been reported before, the multidrug-resistant nature of the contaminating bacteria is novel and important, and highlights the fact that bacterial endophthalmitis might be more difficult to treat than previously thought.

Dr. Huan Pham

As reported by one of the study authors, Huan Pham, MD, all 22 cases of endophthalmitis occurred after phacoemulsification procedures conducted in a 9-day period at their facility in May 2010. The cause of all cases was traced to the use of a batch of trypan blue solution. Each vial in the batch had been sealed prior to use.

In postoperative monitoring, multidrug-resistant P aeruginosa was obtained from the trypan blue solutions. Vitreous samples and/or corneal scrapings and/or aqueous samples displayed resistance behavior identical to a battery of antibiotics.

"This is a fairly novel result. Only 1 case has been reported in the literature. Discussions with the manufacturer traced the problem to the manufacture of the batch of trypan blue," Dr. Pham told Medscape Medical News.

"Contamination of compounded medications should be considered when investigating outbreaks of postoperative endophthalmitis," the investigators write in their abstract.

The involvement of multidrug-resistant P aeruginosa indicates that treatment could be hampered by the antibiotic resiliency of the environmentally ubiquitous infecting bacterium.

"The eye is an immune-poor environment. That, combined with multidrug resistance, could be a big problem in such cases," said Dr. Pham.

The investigators have disclosed no relevant financial relationships.

American Academy of Ophthalmology (AAO) 2011 Annual Meeting: Scientific Poster 16. To be presented October 23, 2011.