I can't help you diagnose or treat your roo but a couple observations from the pic you posted:
1. Is his eye even still there? From the pic it looks like it no longer exists.
2. Is that pus hanging from his ear? What is the creamy glob hanging there?
3. I see little white bubble things that look like little pus pockets or possible bug eggs?
So sorry you're going through this! To me, it looks like there is more going on than just his eye. Wish I could be more helpful but just don't have the experience to help diagnose or treat!