My little guy had the same issue since birth. We were referred to a doctor at Children's Mercy and she suggested that we go ahead with the probing procedure...but my son's eye was still goopy at that time. He was about 11.5 months at the initial appointment, but he had the procedure done right around 13 months. When he had it done, we would squeeze his eye once or twice a day and get the goop out!
The procedure actually wasn't bad. It was awful leaving my son with complete strangers, but from the time the nurses took him until we were in recovery with him was less than an hour. He looked miserable when we first got back with him, but by the time we got in the car he was asking for crackers and by the time we got home he was back to normal. His eye never gooped again and he had no reactions to the surgery.
I am glad that we went through the surgery because the doctor told us that you really can't tell how bad it is until you get in there, and my son's was bad enough that it wouldn't have cleared up on its own and he even needed to have a stint put in to help it stay open which they took out 3 months later. So for us it was a good thing. I think that you need to do what you feel comfortable with. I definitely didn't look forward to the procedure and I was a nervous wreck the whole time, but I feel that my son benefited greatly from the procedure because now he doesn't have to deal with a goopy eye!
Good luck in your decision! Best Wishes