Gary,
Yes, I went through approximately 40 HBO treatments a year and a half ago, following my first sequestrectomy. Coincidentally or not, it was during the time of the HBO treatments that I became very ill with what I thought was the flu, but turned out to be aspiration pneumonia. The HBO treatments led to a serious deterioration of my vision by causing minor cataracts to grow, and my hearing also got worse during that period.
The good news: I got cataract surgery and see better than I have since age 10 and I now wear hearing aids, which I probably needed for a while anyway. I only had to pay for the hearing aids. Thanks goodness for Medicare.
Best of luck with all of your issues.

Stage IV Base of Tongue SCC
Diagnosed July 1, 2002, chemo and radiation treatments completed beginning of Sept/02.