I remember reading about a deaf rabbit - his human used to tap the floor (not heaily enough to be mistaken for a THUMP) to let him know she was coming nearby - he could feel it through the floor. She also used some basic hand signs for things like "bedtime", "up", "treat", etc.
Rabbits are less affected by disabilities than some people - they live in the moment and simply do what they can with what they have. I know of several partially-paralyzed buns, some partially or totally blind ones, and a couple of 3-legged buns.
I once met a blind bunny - survivor of a horrible neglect case - whose brother appointed himself a sort of "seeing-eye bunny". He would sort of nudge him to treats or toys, and would come galloping up to give you a thorough sniffing before permitting you to pet his brother. They were just waiting for their final medical OK and by now are happily settled together in a forever home.
There is a list-serve that I hightly recommend for people with special-needs rabbits - it's called Etherbun. It can be a really busy list, so they have very specific rules about posting - no chitchat, etc - just to keep the info manageable. But it's a great resource. http://www.bio.miami.edu/hare/etherbun.html