Provided is a novel drug for preventing and treating complications after cataract surgery such as secondary cataract and anterior capsular contraction occurring after cataract surgery.The prophylactic and therapeutic agent according to the present invention for complications after cataract surgery such as secondary cataract and anterior capsular contraction comprises, as an active ingredient, 4-fluoro-5-{[(2S)-2-methyl-1,4-diazepan-1-yl]sulfonyl}isoqu inoline (ripasudil), a salt thereof or a solvate of the same.