Does a person still have graves disease when the thyroid has been killed off with the radioactive iodine?

Yes, I have it and have had the radioactive cola. I have to take synthroid pills for the rest of my life. If i don't The doctor says it can be hurtful to my body. I might get puffy bulging eyes and getting really fatiged. The worst- I might go to sleep and slip into a coma. SO i take my pills everyday.