depth of field only on edges

Hi there.

I’m trying to make an effect where that works like DOF but instead of using the scene depth I want to use screen’s uv, so only would have the effect in the edges of the screen and having clear the center. Is an affect that apears in Resident Evil 7. I tried creating a pst-process material blur with a custom node but that blur is not like unreal’s DOF and RE7 effec.

Thanks