Hi Bitter,
I too know quite a few who had RAI and the TED got worse. Also know many who had RAI and it stayed the same or settled down. It is hard to make generalizations.
RAI does not stop TED from happening. It does nothing to stop it but I cannot say it causes it. Now it does seem that if you take steroids with the RAI it does seem to decrease the TED.
I recommend that people who are thinking about RAI use the search engine and look up posts on the subject.
Jake
On-line Facilitator