The present invention relates to 6-substituted isoquinoline derivatives having the general Formula I wherein X is O, S or NH; Y is OH or NH2; m is 0, 1 or 2; n is 0 or 1; o is 0 or 1; R1 is H, when Y is NH2; or R1 is H, (C1-4)alkyl or halogen, when Y is OH; R2 and R3 are independently H, (C1-4)alkyl or halogen; R4 is H or (C1-6)alkyl, optionally substituted with halogen, (C3-7)cycloalkyl, (C6-10)aryl or a saturated 5- or 6-membered heterocyclic ring comprising 1-3 heteroatoms independently selected from O, S and N, the (C6-10)aryl and heterocyclic ring being optionally substituted with (C1-4)alkyl, (C1-4)alkyloxy or halogen; R5 is H or (C1-4)alkyl; or a pharmaceutically acceptable salt thereof, with the proviso that the compounds of Formula I wherein X is O, Y is OH , n is 0 and m+o=2 are excluded, to pharmaceutical compositions comprising the same, as well as to the use of said 6-substituted isoquinoline derivatives for the preparation of a medicament for the treatment of ROCK-I related disorders such as glaucoma, hypertension and atherosclerosis.