In our area it depends on your GP as to where you get seen, even if you go to the hospital for diabetic check ups. Some GP practices opted to use local Opticians' services, others ( like mine) opted to have the mobile unit from the hopsital that comes round annually and sets up the machine in one of the nurses rooms. When I missed the mobile service because i was away, I had to go the main eye hospital in Oxford for mine, and it was absolutely rammed, so I can see why your hospital might refer you back to your GP option.