POLYTRIM OP SOL

My son is about 22 pounds and is 6 months old. He has seen his pediatrician and they put him on POLYMIXIN SULF/TMP SOL FALCON OP for a "closed tear duct". His eye isn't getting any better though. It is only his left eye, but, his eye sticks shut, his eyelashes are constantly sticking together, it waters all the time, and I have to constantly take a warm wash cloth just so he can see out of it. When I do what his pediatrician says by putting 2 drops in his eye 4 times a day for 5 days, it seems to help, but, when he don't get it in his eyes anymore, it goes right back to doing the same thing. I just want to know SHOULD I CONTINUE PUTTING THESE DROPS IN HIS EYES OR SHOULD I CONSIDER ANOTHER ALTERNATIVE? I hate to see his eye like this all the time and I am at my wits end with it. They say he "can" outgrow it by 2 years of age, but I don't think I want to have him or me going through this until then. Please tell me what you think! Thank you, MARISSA BITHELL