Adding Volume to Inner Corners of Eyelids?

Dear Thenoseknows
The best method of getting out of trouble is staying out of trouble. In eyelid surgery this means preserving eyelid folds, and natural fullness. One can always have a little more surgery if it is desirable.
Regarding your situation, replacing fat into the upper eyelid post surgical hollows is very easy to describe but achieve a result that is functionally and aesthetically acceptable is very difficult to the point of being improbable.
More achievable alternatives include placing fat or filler in the brow and subbrow tissues. This fills up the fold and can help hide the hollows.
Because of the vascularity of this area, the subbrow area should only be treated by those with surgical expertise of this area. Don't get this type of treatment in a medispa.
Dr. Steinsapir

In Plastic surgery, one of the key principles is to replace lost tissue with the same kind of tissue, or as close to it as possible.
Since you had a blepharoplasty, I assume fat was taken out. It follows the best solution is fat replacement.
Luckily for you, fat grafting techniques have been refined to a level of high reliability when using fine cannula techniques.
For upper and lower eyelid cases there is a wonderful 18 gage blunt cannula which can achieve very subtle results.

The only options for replacing volume in the upper eyelids following aggressive blepharoplasty are: fat grafting or injectable fillers.
I've used injectable fillers for this condition with good (not great) results. Fat grafting in the right hands is another option that would have greater cost and downtime.
Feel free to post / email me a full facial photo, and I could give more specific advice.
Best regards.