There are no FDA approved fillers for under the eye. Most fillers only have FDA approval for Naso Labial Folds. At this date there is only one FDA approved filler for lips (Restylane).
Risking long term or permanent fillers under the eye is not worth the potential negative results. Restylane injected properly under the eye typically lasts longer than it does in other areas, so you'll likely see the volume you are enjoying longer than you might think.
Fillers have been used for many years in "off label" application.The "off label" use of fillers is chosen independently by each physician. Off label is not illegal and in most cases not dangerous. It simply means the filler is being used in a way or in an area of the face that was not included in the FDA clinical studies.
Most U.S. physicians who treat under eye hollows with fillers will generally choose Restylane or Juvederm. Both fillers consist of hyaluronic acid gel which is a degradable product most closely resembling natural skin tissue.
Careful injection of these hyaluronic gels at the proper depths and within the anatomical safety boundaries generally gets good results.The nice "fail safe" of HA gels is that they can be dissolved quite easily if the patient is not happy with the results.
There are fillers which are "contraindicated" in certain areas - meaning they are known to create a problem or are suspected to be capable of creating a problem.
Because the tear trough is such a sensitive area, and the skin is thinnest there, any "lumping" will show. It is also a highly reactionary area and more easily bruises or swells.
Injector techiqiue and precise knowldege of eye area anatomy is extremely important. Pick experience over price promotions - particularly for eye area injections.
It sounds that you are happy with your Restylane. If you were my patient I would encourage you to accept the temporary nature and appreciate the safeguards that come with it.
