PROPHYLACTIC OR THERAPEUTIC AGENT FOR OPTIC NERVE DISORDERS COMPRISING 4,6-DICHLORO-1H-INDOLE-2-CARBOXYLIC ACID DERIVATIVE OR SALT THEREOF AS ACTIVE INGREDIENT
Disclosed is a compound useful as a preventive or therapeutic agent for optic nerve disorders, an inhibitor of retinal ganglion cell death or an agent for restoring the expression level of a neurofilament light chain, particularly a compound capable of exhibiting the abovementioned pharmacological activities when administered orally. A 4,6-dichloro-1H-indole-2-carboxylic acid derivative or a salt thereof can significantly inhibit the decrease in the number of cells in a retinal ganglion cell layer of an NMDA-induced rat retinal disorder model when administered to the model orally, and can also restore the decrease in the expression level of a neurofilament light chain in a retina of the model when administered to the model intravitreally (intraocular local administration). Therefore, the compound or a salt thereof is useful as a preventive or therapeutic agent for optic nerve disorders, an inhibitor of retinal ganglion cell death or an agent for restoring the expression level of a neurofilament light chain.