Do you recall the name of the Expert who helped you last time? If so, I can send this question to him. Or I can answer it for you if you would like.
I am assuming that you are talking about your anisocoria (pupils of different sizes). Once you have had a good neurologic workup (including MRI), there is probably no need to keep chasing it. I don't think you really need routine follow-up MRIs unless there is a change that is noted. Or unless you develop some other neurologic symptoms. Most anisocoria are benign.
Hope this helps and thank you.