Err who told you that cataract surgery causes retinopathy?
Retinopathy is the blood vessels at the back of the eye and the affects of the blood sugar level, the cataract is just the eye lens harding and clouding over, it blocks the eye's ability to see through the lens, but doesn't effect the actual eye's ability of sight..
The surgen is replacing the lens with a new one, the risks of anything going wrong is reasonably low, risk factor of infection, problems with raising eye ball pressure etc
My OH is T1 and he had his first cataract operation last year, the worst part of the operation was being one of the last of the morning session so a lot of hanging around, and the 11 pre-operation eye drops they put in... The actual operation went very quickly indeed..