Neil,
I live in Arizona and have met Dr. Brian McKay. He is an eye specialist/researcher at the University of Arizona.
A few weeks ago he gave a presentation at the U of A about implanting retinal cells in pwp. (I'll find that link and post it) From his presentation, it sounded like he is also a consultant for Spheramine (Titan / Bayer) because he talked about his association with ongoing trials using retinal cells.
Here is the link to his talk:
http://streaming.biocom.arizona.edu/event/?id=20780
Also I spoke to him a few months ago at a MJ Fox Science Roundtable here in Arizona and he proposes to do something slightly different from Spheramine - he would still use retinal cells, but autologous - use the patient's own retinal cells so there will be no risk of rejection.
A local PD association tried desperately to get funding for his research this year. But unfortunately the timing for getting an application submitted and through the approval process was bad, so to our great disappointment, he did not get funding this year.
He is still testing on animals. But I'm following this closely. Whenever / If ever there is a phase I trial - I would be interested in it - and glad to find such promising research so close to my home.