[Survey of severe contact lens-associated microbial keratitis in Japan].

PURPOSE: To understand the current state of severe contact lens (CL)-associated microbial keratitis in Japan. METHOD: The survey was conducted by the Japan Contact Lens Society and the Japanese Association for Ocular Infection in 224 facilities from April 2007 to March 2009. Patients who were diagnosed with CL-associated microbial keratitis and hospitalized for treatment were enrolled. Clinical characteristics of the keratitis, microbiologic findings and the status of CL hygiene were studied. RESULTS: A total of 350 patients were investigated, with an average age of 28.0 (9-90) years. Acanthamoeba was identified in 85 (24.3%) corneal specimens and Pseudomonus aeruginosa in 70 (20.0%) cases. One hundred ninety six (56.0%) patients were frequent replacement soft CL users. Extended wearing of daily-use CLs was found in 77 (22.0%) patients. Only 67 cases maintained good CL hygiene by daily rubbing-washing and the poor CL care situation was reviewed. CONCLUSION: The most frequently detected pathogenic microorganism was Acanthamoeba, followed by Pseudomonus aeruginosa. Our survey showed the importance of keeping good CL hygiene by proper lens care, and improvement of CL-related social regulations is urgently needed.