Microbiological Investigations of ReNu Plastic Bottles and the 2004 to 2006 ReNu With MoistureLoc-Related Worldwide Fusarium Keratitis Event

Eye Contact Lens. 2016 May;42(3):147-52. doi: 10.1097/ICL.0000000000000175.


Purposes: The purposes of this study were to determine whether the contact lens solution RevitaLens Ocutec (containing the antimicrobial agents alexidine and polyquaternium-1) would inhibit Fusarium organisms when heated in ReNu plastic bottles; whether alexidine would inhibit Fusarium organisms when heated in non-ReNu plastic bottles; and whether an alexidine-neutralizing compound leaches from heated ReNu bottles.

Methods: RevitaLens and an alexidine solution (0.00045%), previously stored in ReNu bottles at room temperature (RT) and 56°C, were incubated with 7 different Fusarium organisms. The alexidine solution was similarly stored in seven non-ReNu plastic bottles and incubated with these same organisms. To determine if an alexidine-neutralizing compound might be leaching from heated ReNu bottles, phosphate-buffered saline (PBS) was incubated at RT and 56°C in ReNu bottles, combined with alexidine, and then tested for anti-Fusarium capability.

Results: After being heated in ReNu bottles, RevitaLens retained its anti-Fusarium capability, whereas the alexidine solution did not. The alexidine solution heated in seven non-ReNu plastic bottles retained its anti-Fusarium capability. The alexidine solution retained its anti-Fusarium capability when incubated with a PBS solution that had been heated in ReNu bottles, indicating, microbiologically, that an alexidine-neutralizing compound did not leach from the heated ReNu bottle.

Conclusions: Alexidine uniquely fails to inhibit Fusarium organisms when heated in a plastic ReNu bottle, but not in seven other plastic bottles, whereas the anti-Fusarium capability of RevitaLens (containing the antimicrobial agents alexidine and polyquaternium-1) is unaffected by heating in a ReNu bottle. There does not seem to be an alexidine-neutralizing compound leaching from heated ReNu bottles. An interaction between alexidine and its heated ReNu bottle may have been a critical factor in the worldwide ReNu with MoistureLoc-related Fusarium keratitis event of 2004 to 2006.

Publication types

  • Comparative Study

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Biguanides / pharmacology*
  • Contact Lens Solutions / pharmacology*
  • Contact Lenses / microbiology
  • Drug Packaging / instrumentation*
  • Drug Storage / methods
  • Fusarium / drug effects*
  • Fusarium / growth & development
  • Glass
  • Hot Temperature
  • Plastics
  • Polymers / pharmacology*


  • Anti-Bacterial Agents
  • Biguanides
  • Contact Lens Solutions
  • Plastics
  • Polymers
  • polyquaternium 1
  • alexidine