Orbital Fat Prolapse
Actually, we do these excisions with some regularity, (in addition to the bleph and ptosis previously mentioned) and the coding that we use is 67412, as doctor must breach the orbit to make the excision. 374.34 (fat pad hernia - orbit) is the diagnosis code that we use.
As previously recommended, I would say check with your physician to verify the coding. Two of the three procedures mentioned here are subtly different, but the excision of orbital fat that we typically deal with, and that I'm thinking of, presents very differently. Good luck!