A compound represented by the formula (1):wherein R1 represents a hydroxyl group, a dimethylphosphynoyloxy group, etc.； and R2 and R3 represent a methoxy group, etc.,or a pharmaceutically acceptable salt thereof can reduce a score of telangiectasia around the meibomian gland orifices and a number of obstruction at the orifices, so that it is useful as a prophylactic and/or therapeutic agent for meibomian gland dysfunction.
