Thanks for the extra information, and the link.

Here is a similar link, which has a bit more information about visual hallucinations. After you have clicked on this link, click on the link which says "EYE PROBLEMS YOU MAY EXPERIENCE".

Parkinson's UK - Eye problems

The clear message seems to be that the vision problem(s) you are having could well be caused by PD, and that PD professionals should be well aware of this. I really don't understand why you are having so much trouble getting appropriate responses from the PD professionals you have consulted.