It sounds like your doctors have performed extremely extensive testing. You should follow up with them as they have recommended. Your GP or a local eye hospital may be able to refer you for a second opinion.

None of us are qualified to even guess at a diagnosis or offer medical advice. I'm locking this post for that reason, as I don't want you to be told something potentially dangerous or misleading.

I wish you the best. Please feel free to post non-medical questions in this subreddit or otherwise participate.