While injectable compounds developed for filling skin wrinkles and superficial skin indentations (such as hyaluronic acid, calcium hyroxylapatite, or poly-L-lactic acid) may be used in augmenting the tear trough or other areas of depression along the upper cheek, they are temporary in effect and not inexpensive.
Dermal fillers are intended for injection into the dermis (second layer of the skin) or subdermally at the dermal-subcutanous fat junction (diagram). Unlike other facial skin, the eyelid skin has an extremely thin dermis and contains almost no subcutaneous fat (not to be confused with the much deeper orbital fat).
If a dermal filler is injected superficially when a volume deficit is much deeper (such as in a hollowed eyelid missing adequate orbital fat), the effect may resemble built-up putty hiding a bad dent or crack. Not only can the "repair" look as obvious as the problem and disappear all too quickly, but the underlying damage remains unaltered.
Deeper placement of "permanent" (ex: liquid silicone) or "semi-permanent" (ex: calcium hydroxylapatite) injectables into other eyelid tissues or the orbit risks migration into the spaces surrounding the eye as well as other unknown long-term chemical consequences.
Most patients seeking orbital fat grafting have already tried injectable fillers (most often, hyaluronic acid fillers) and judged the transient camouflage to be unsatisfactory.