I second what Christine said. HBO can be done more than once. It help me tremendously. I could not eat anything before going in there, now I am eat soft foods. My HBO Dr even told me that I may need to come for me HBO if I get more non-healling ulcers. The vision, I did experience some issues, but that have now gone away. That is a temporary issue. It was well worth it, to be able to get off all the pain meds. I do not have any mroe exposed bone.