What Causes Blocked Tear Ducts And Constant Watery Eyes?

I have recently been diagnosed with blocked tear ducts and have continuous watering of the eyes and I am soon to see an opthalmic surgeon.My problem at the moment for a few weeks noiw is yellow discharge,itching soreness and redness in one eye.Have treated this with antibiotic drops 3 times but to no avail.I am now trying salt washes but nothing happening as yet.Is there anything else That I can do before going to hospital in a week.