Purpose: To investigate the trend in the number of Acanthamoeba keratitis (AK) cases in Japan.
Method: A survey was conducted in 48 university hospitals. Patients who were diagnosed with AK from January 2007 to December 2011 were enrolled. The trend in the number of cases and the type of contact lenses (CLs) that patients used were studied.
Results: A total of 524 patients was studied. The numbers of AK cases in each year, from 2007 to 2011, were 105, 152, 155, 65, and 47. The number dropped markedly after 2009. The percentage of conventional soft CLs and frequent replacement soft CL users that needed daily care such as rubbing-washing also dropped after 2008.
Conclusion: The number of AK cases in Japan has been decreasing in recent years. The cause is uncertain, but one possibility is that information about proper CL care promulgated by ophthalmic societies in recent years is producing results.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 118: 28-32, 2014.