Hi. I'm online and happy to answer your question today.
are you available to chat?
I do not believe trying to correlate your wife Graves disease with some unknown eye disease in her maternal grandfather is possible. Who knows what that family member had over a century ago? The good news, however, is that much has been learned about Graves disease in the last few decades
The steroids will cause your wifes weight gain and this is to be expected. If it is a large problem you could discuss the possible addition of "steroid sparing" medicines to try and lower the steroid dose, if possible.
It is hard to tell the future, even for us doctors :) There are a number of things that can be done for your wife's orbital disease, both medical and surgical. It is important that while she is in the active phase of her disease process she be followed closely by an ophthalmologist for any evidence of corneal exposure, optic nerve compression etc.
If you are having a problem finding ophthalmologists in your area knowledgeable about Graves disease you might consider contacting someone at Moorefields Eye Hospital, since I see you are in the UK). I'm sure they will be able to hook you up with a physician comfortable treating your wifes condition.
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