I know a teacher who married a gal w/that kind of age gap. They waited until she graduated to make it 'official'. He divorced his wife (w/kids) to do it. So it can work, depending on your definition of 'work', I suppose.
Personally, tho I always found the guy to be a bit of a perv. The sort always making psuedo-sexual comments to his students. And he was definitely getting off on being the 'daddy figure' in that relationship.
Given that the fellow had daughters w/his first wife, I figured it was probably a good idea he & his wife split & those kids got away from him.
Heard enough?
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh