Guys, thanks for the encouragement you gave me last week. It was much appreciated. I got back from the hospital and the laser surgery went very well. The retinal damage has been corrected - not sure what they did, but the laser technique focussed on the blood vessels around the retina - maybe they were cauterized, I don't really know. Having diabetes, there is a greater incidence of eye damage than normal.
The retinal scans are ok. I've been told to scale back all exercise for the next 4 weeks, but at this time of year in the UK, that's not so hard to achieve! They say I can do light sessions at the gym, but I need to keep it brief with plenty of rest inbetween activity. Sustained activity is a no-go, so no riding allowed. Basically take it easy.
At least the forums are nice and passive?