My Son Is 18 Months Now. I Noticed A Ridge

My son is 18 months now. I noticed a ridge in the middle of his forehead when he was 2 months .I asked a neurologist and he said it is a metopic ridge and it'll not affect him unless the shape of her skull but I'm worried because his skull has a triangular shape and the ridge is very noticeable. He has no problems or delayes till now .
Does he need a surgery or not?
Does the ridge disappear by time?
Is there a specific age to make the surgery??
Does he need a CT?
Thanks in advance.