We encountered two patients referred for treatment of Graves' eye dise
ase who had atypical features and were found to have carotid-cavernous
fistulae. The relevant clinical findings and investigations used to m
ake this important distinction are described, and the factors involved
in the initial diagnostic confusion are analyzed. A correct diagnosis
leading to proper treatment was made once atypical features were take
n note of and alternative diagnoses considered, despite the context of
presumed Graves' eye disease. We conclude that these two entities are
quite different but have enough similarities to overlap in certain cl
inical contexts.