Can Dermapen be used directly under the eye for wrinkles or is tissue there too thin/delicate?

Yes by an expert "micro needling" doctor at a 1mm or less penetration depth. I might add PRP/Vit K-C/AFSC mix to the needling. Cost $500. 

The Dermapen technology is an
ergonomic pen that is able to treat all contours and hard-to-reach areas on the
face, including the delicate under-eyes and lip area. Using dermapen
around the eyes for wrinkles is very effective and will help to improve these
fine lines, as well as restore skin tightness and radiance. We recommend this
treatment at our practice located in New York City.

All of the
microneedling pens can be used directly under the eyes, if the person doing the
procedure is well skilled and well versed in the proper use of the pen. These
pens have different needle lengths, and the shorter ones can do great things
under the eyes, providing the provider is skilled.