Tear troughs and undereye hollows are some of the most common periorbital aesthetic deformities. While they are located in the lower eyelid region they are not necessarily the same. Tear trough are typically described as discrete indentations located more at the medial orbital rim area and are the result of aging or tissue thinning creating a skeletonized region. Conversely infraorbital hollows often represent an infraorbital skeletal deficiency which is why the infraorbital fat pockets above them appear to be protruding.
These lower eyelid depressions are most commonly treated by a variety of injectable fillers or fat. But implants have a role to play particularly when an infraorbital rim deficiency exists. The best implants to use in the undereye area are custom made infraorbital implants as they saddle the bony rim and are designed to be a true extension of the bone.
But standard infraorbital rim implants do exist and are known as tear trough implants. My favorite to use is the extended tear trough implant because it is really an infraorbital-malar implant style that covers up to 6cms length along these areas which is substantial. If you look carefully at their design they have a circular indentation in them for relief of the infraorbital nerve. At the least that should keep the from being reversed as they are located at the inner aspect of the implant.
There are multiple incisional approaches to placing the extended tear trough implant from intraoral to subciliary and transconjunctival lower eyelid approaches. I prefer the external transcutaneous approach through a subciliary eyelid incision as it avoids the risks of persistent infraorbital nerve dysesthesia and implant malposition from an intraoral approach and placement difficulties associated with an inner eyelid incision. But there is one caveat…keep the lower eyelid incision only partial length. This is not a lower blepharoplasty where excess tissue is being removed. This is an access incision so it can be a partial lower eyelid incision with only a millimeter or two of a lateral cantonal extension. This will denervate less of the orbicularis muscle. Between a limed incision and more orbicularis muscle preservation the risk of lower lid retraction is minimized. When placing the implant I just cut a larger open wedge for the infraorbital nerve. There is not a good reason to wrap the implant tightly around the infraorbital nerve as it provides no aesthetic benefit.
Once in position I use a single microscrew (1.5mms) through the main body of the implant to the anterior zygoma. Once the implant is secured fat transposition can be done over the medial aspect of the implant. Infraorbital fat pockets may protrude above the implant level so they can be effectively used for greater soft tissue coverage over the implant which is of greatest benefit medially.
Closure is done with a lateral canthopexy and a soft tissue cheek suspenseon to the lateral orbital rim. In some case one may feel more comfortable to have a lateral lower eyelid suspension suture taped to the forehead for 3 to 5 days after surgery.
The extended the trough implant is, in some ways, a poor man’s custom infraorbital-malar implant give its bony surface area coverage. While it does not wrap around the infraorbital rim as a custom implant would, screw fixation allows the implant to sit a bit higher than the level of the infraorbital rim if desired.
Dr. Barry Eppley