The present invention provides a pharmaceutical composition for removing drusen, suppressing formation of drusen, and/or treating and/or preventing age-related macular degeneration comprising the compound of formula (I) wherein Ra is independently selected from the group consisting of halo, hydroxy, alkyl, halo-substituted alkyl, aryl, halo- or alkyl-substituted aryl, alkoxy, hydroxy- or carboxy-substituted alkoxy, aryloxy, halo- or alkyl-substituted aryloxy, CHO, C(O)-alkyl, C(O)-aryl, C(O)-alkyl-carboxyl, C(O)-alkylene-carboxy ester and cyano, and m is an integer selected from 0 to 4.
