I looked at the pics over and over. I'm afraid I don't have much to suggest; and this is a long shot at that; but is it possible she had a bot fly?? I've seen them in cats at the vet clinic I used to work for. They are not common but as you mentioned the other treatments haven't been working, it's possible that's what it is. Especially with how you described how it initially showed up. On PETMD's site it mentions:
Lesions (caused by the larvae in the eyeball)"
via: Botflies (Maggots) in Dogs | petMD
Again it's a long shot, but I figured since you're looking for any suggestion it was worth mentioning. Good luck and I hope it improves!