If you had permanent eyeliner in the past, then Latisse can be used without any problem. The question of when after permanent eyeliner can you begin Latisse suggests that one might want to do both. Since Latisse is so successful at making eyelashes thicker, longer, and darker -- and since Latisse also sometimes makes the base of the lases darker by hyperpigmenting the skin, it seems not necessary to also do permanent eyeliner.
So my suggestion is to try Latisse alone by itself, and if you are not happy with the appearance, then consider permanent eyeliner later.
From a medical perspective, you could start Latisse about one week after the permanent eyeliner has been completed.