Blocked Tear Duct and Causes

I have had blocked tear ducts in both eyes for over a month. I saw an opthamologist last week and he probed my ducts.  That worked for about a day or two and the went back to being clogged up again. He said it could take 2 or 3 times to work so I scheduled another appointment for next week. Is is possible contiued probing will take care of this? Anything I could be doing at home to help the situation?
also, i am 5 months post RadioActive Iodine treatment for Thyroid Cancer. I have been reading alot of forums and studies since this blockage began that suggest RAI treatment can cause salivary gland and tear duct issues even months after initial therapy.  Anyone heard of this... I have convinced myself this is the cause.  The RAI was necessary, but I just want to know what I am dealing with.  Thanks!

[Sandy Feldman, MD, MS]

I would discuss this issue with your eyeMD. RAI does not usually cause blocked tear ducts.  Surgery may be needed to create an opening from upper tear drainage into your nose, known as dacryocystrhinotomy [DCR].
Dr. Feldman

Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California

[tribZ4]

I have thyroid cancer and had RAI in 2004 and didn't realize the connection with the tear ducts until recently.  In 2006 I had surgery on my left tear duct which was completely obstructed.  The right one was 90% obstructed which I lived with until last week when I had lacrimal tear duct surgery on this eye.  It's unbelievable how many other problems stem from thyroid cancer.  I was told the only way to cure clogged tear ducts is with the surgery.