PROBLEM TO BE SOLVED: To provide a retinal pigment epithelial cell protectant.SOLUTION: The present invention provides a preventive or therapeutic agent for an eye disease caused by retinal pigment epithelial cell dysfunction or degeneration, the agent comprising (S)-4-fluoro-5-(2-methyl-1,4-diazepan-1-ylsulfonyl) isoquinoline represented by the following formula (1), its acid addition salt or their solvates as an active ingredient.COPYRIGHT: (C)2016,JPO&INPIT【課題】網膜色素上皮細胞保護剤の提供。【解決手段】下記式(1)で表される(S)-4-フルオロ-5-(2-メチル-1,4-ジアゼパン-1-イルスルホニル)イソキノリン、その酸付加塩又はそれらの溶媒和物を有効成分とする網膜色素上皮細胞障害若しくは変性による眼疾患の予防又は治療剤。【選択図】なし
