I too spent some time (last 4 1/2 years of my career) with a med cat of being unable to deploy (I spent a couple of years needing to be within spitting distance of a hospital with a potentially serious eye condition which could lead to a detached retina) but was allowed some latitude with travel to Europe with SMO approval. However, my flying was very sporadic at the time as I was flying a desk for the PT for the last 5 years of my PAS career. I eventually went to SME at Henlow for a permanent medical downgrade where they did not fuss too much about the eye but were more concerned with "how far can you run". I came out with the same med cat as I went in, still able to fly (admittedly in the back of ISTAR), and ended my career on time 2 years later. I have to say that I found the medics very supportive during the whole period - they were very fair.