Therefore there must be SOME evidence to say that it does....if you're facing losing your sight then you'll try anything, no matter how low the odds!

Yes exactly. Obviously I am no specialist but I found this article which is encouraging

Improvement in visual fields in a patient with melanoma-associated retinopathy treated with intravenous immunoglobulin.

How many people get treatments, for all kinds of illnesses, which are administered more in hope than anything else?
This is a situation that ANY of us could find ourselves in - and that's scary!!! Not to mention unacceptable!!!

It is very scary indeed - and totally unacceptable.  As you say, there are treatments given in the hope that they will work. Generally they are termed as clinical trials (for treatments  such as cancer).