Filler vs fat graft over hollow upper eyelid?

Although both fat and filler injection are safe in upper eyelids, filler is much more predictable than fat injection, especially in an that has been previously operated on with scar tissue and less blood supply. 

A combination approach will give the most improvement. Fillers, lasers, and microneedling/PRP can improve under the eyes. My patients try to get non surgical treatments to avoid surgery. We use PRP and stem cells there often. I suggest consulting with an expert to develop a treatment plan best suited for your short and long term goals. Best, Dr. Emer

Ideally fat would be better but there are not that many doctors with enough experience and expertise to do it well... A hyaluronic acid filler is easier and safer but requires periodic treatments.