I know it is a rare occurrence but I have a sick blue Gouldian

it was not looking well so I gave it and it's aviary companions a treatment of moxi for fear of air sack mites. It seemed to pep up for a week or two then back to fluffed up and lots of sleeping. I put it in a hospital cage and after a week it seemed to be a picture of health so back to the aviary it went. Two weeks later it's right eye was weeping and back to being fluffed up and resting. Took it to the vet and it got put on a Psittavet. Spent two weeks in the hospital cage and bird was back to normal, when released into a holding aviary it was full of beans for another week until both eyes started to weep. She's a fighter but I think this time it's not good, any help would be appreciated.
Cheers
Ron