Thanks for adding to this one. I can see a similar train of thinking here, in that I also suspected other things as possibly being involved, such as dental or sinus issues, and I had a sinus revision procedure only a couple of years or so ago. In my case the MRI did not reveal anything sinister but equally I still had no real answers, so this MRV procedure in reference to IH is interesting.
Until I had my MRI I was of the thinking that some blood supply issue could be the underlying reason, perhaps a problem putting pressure on the optic nerve for example, and IH sounds like it could do something like that, just not in a way I'd considered before. You mention eye pain, and I believe I've had the same, it can be quite piercing, almost a stabbing like pain, but usually doesn't last long.
Your mention of case rarity may well be correct too, especially when PVD is also involved. It'll be interesting to see how things pan out in your case, although I can't help but wonder if the lumbar puncture may offer a one off fix, or if I'm correct, and the procedure is to remove some cerebrospinal fluid to reduce pressure, if it may become needed more often in some cases. Thanks for the info and good luck with your situation.