I am personally against the injecting of any filler (fat or off the shelf filler) around the eye. I do not like the risk of blindness with these procedures. Despite that many doctors do inject fillers in these areas with good results and happy patients.
There are inherent differences between restylane and fat. The restylane for one is guaranteed to go away so there would be a need for repeat injections for ever. Fat if it survives the transfer process on the other hand will be there forever. You need to be aware though that injecting fat in these areas has a high risk of forming lumps. This is probably due to the constant muscle movement of blinking. I prefer to place a fat graft as a sheet of fat right on the bone rim via a blepharoplasty incision. This gives me a more even result with risk of blindness or lumps.