This is the 14th century Byzantine Empire we're talking about here. They kept records in languages we can read, as did their neighbors and eventual conquerors.

This is the 14th century Byzantine Empire we're talking about here. They kept records in languages we can read, as did their neighbors and eventual conquerors. There's nothing about this discovery that is inconsistent with our prior knowledge of their medical technology, and no reason whatsoever to speculate that they were using some kind of secret lost medicine.