It was the astigmatism that got me too on the Class 1 initial, not something I realised I had. However, I am also on a deviation so all is not lost and I can commence my CPL training. .
I believe that the guys at Gatwick will do everything they can to get you through the medical, but if you fall outside the criteria then it's simply no Class 1. However, I think I'm correct in saying that the Class 1 reissue criteria aren't as tough as the initial.