Article History
Received: 16 December 2014
Accepted: 15 May 2015
First Online: 10 July 2015
Competing interests
: NY is a consultant for Kissei Co., Ltd., Nagano, Japan and Rohto Co., Ltd, Osaka, Japan. SK is a consultant for Santen Pharmaceutical Co., Ltd, Osaka, Japan and Otsuka Pharmaceutical Co., Ltd., Tokyo, Japan. The remaining authors declare no conflict of interest.