By Dr. David Deng
DO YOUR PATIENTS complain that they always look tired in the mirror? Is the hollowness underneath their eyes so severe that no amount of makeup can conceal it?
The eyes are usually the first facial feature that one will notice when looking into the mirror. In recent years, an increasing number of both men and women are seeking filler treatment to resolve their tiredlooking eyes. Therefore, it is important for injectors to know how to use fillers to effectively treat undereye hollowness.
What causes undereye hollowness?
In order to treat undereye hollowness effectively, we need to first understand what causes it. Undereye hollowness worsens the appearance of dark eye circles and makes one look tired and old. This happens because of either a true or pseudo tear trough deformity. In true tear trough deformity, the skin beneath the eyes is attached directly to the underlying muscle and orbital bone causing a concave appearance.1 This is more evident in some individuals due to genetics, and start early on in the teenage years.
On the other hand, pseudo tear trough deformity is caused by aging due to deep medial cheek (medial sub-orbicularis oculi and deep medial cheek) fat pads [Fig. 1] volume loss with aging. This leads to a lack of structural support of the undereye therefore revealing hollowness underneath the eyes.
A test that you should perform prior to filler treatment is to push the deep medial cheek fat pads superiorly to visualise if the patient’s undereye hollowness improves. If it does improve, the tear trough deformity has a component of being caused by volume loss in the deep medial cheek fat pads.
Often, most patients have a combination of both true and pseudo tear trough deformities. Both are anatomical problems that can only be solved by filling the hollowness, and more hours of sleep or hydration will not resolve this issue.
Fig. 1: Deep Facial Fat Pads
Why is this important to differentiate?
The choice of filler and where to place the filler will depend on your assessment of what is causing your patient’s undereye hollowness. In pseudo tear trough deformity, the deep medial cheek fat volume loss should be replaced by using a thicker filler for more projection and lift. This should be injected deep into the medial sub-orbicularis oculi and deep medial cheek fat pads.
In the treatment of true tear trough deformity, a finer and less hydrophilic filler should be used to fill between the skin and muscle in the undereye. Not only is the type of filler important, the amount of filler and injection technique are keys to avoid complications from overfilling such as lumps and the Tyndall effect.2
Filler to correct the tear trough can be performed either using direct needle or cannula technique. My preference is to use a cannula even though it is technically more challenging because it helps to reduce the risk of complications and is more comfortable for patients. Further, using the cannula technique is a one-step approach to fill both the deep medial cheek fat pads (in pseudo tear trough deformity) and the undereye (in true tear trough deformity) using the same single-entry point.
Fig 1: Needle vs. Cannula Technique | Pic Source: InjectMate
A 25 gauge cannula is inserted after a 25 or 23 gauge needle is used to create an entry point at the lateral side of the cheek. The cannula threads through the tissues without piercing through any veins leading to less bruising. It also provides the injector with much better tactile feedback of the tissue planes to inject filler at the correct depth. It takes experience to feel and recognise the correct tissue depth using a cannula.
It is important for injectors to understand that the tear trough should generally be underfilled. This is because the skin underneath the eyes is extremely thin and a tiny amount of filler placed in this area will cause a significant difference. Instantaneous results with tear trough filler will generally look even better in 1 to 2 weeks’ time as the filler particles absorb water leading to volume expansion. Therefore, it is important to slightly underfill in the first treatment session followed by a follow up in 2 to 3 weeks to decide if a filler touch up is required, for the most natural outcome. It is natural to have slight residue hollowness underneath the eyes after filler treatment. This provides some margin for fluctuations of the filler when the body is more hydrated in the morning leading to filler volume expansion, or less at night.
How painful is tear trough filler?
Contrary to popular belief, tear trough filler is not as painful as it looks. The skin underneath the eyes is thin and adheres to the underlying muscle and bone. Therefore, patients may feel a slight discomfort rather than a sharp pain when the cannula glides and dissects between the skin and underlying structures. It is important to discuss pain management as part of the consultation prior to filler treatment.
During cheek filler procedure to correct pseudo tear trough deformity, patients may feel an initial soreness as the cannula bypasses the muscle containing nerves in the more superficial plane to reach the deep medial cheek fat pads. Injecting fillers into the deep medial cheek fat pads itself is an almost painless manoeuvre. Factors that will help to reduce discomfort include topical anaesthetic to the skin before the procedure and lidocaine that is present in the fillers.
How long do results last?
This depends on the type of filler that you as the injector choose to use and how quickly the patient’s body metabolises the filler material. On average, the finer hyaluronic acid fillers used for true tear trough deformity last between 6 to 9 months whilst the thicker hyaluronic acid fillers used for deep medial cheek fat pads’ volume replacement last between 12 to 18 months. In my practice, I also use collagen stimulators such as calcium hydroxyapatite and polycaprolactone to fill the cheek to provide longer lasting results.
Is this a risky procedure?
Undereye filler is an advanced procedure requiring excellent understanding of facial anatomy and experience in injecting. When performed by a skilled practitioner, it is associated with minimal risks. Bruising and swelling may rarely occur in the delicate undereye area which usually resolves in a few days to a week.
Complications such as filler lumps and the Tyndall effect caused by too superficial and/ or too much filler injected can be avoided with experience.
In summary, it is important to differentiate between true versus pseudo tear trough deformity in the treatment of undereye hollowness using fillers. This will have an impact on the type of fillers used and techniques employed for the most effective and natural results.
Ross L. Stutman, MD, Mark A. Codner, MD, Tear Trough Deformity: Review of Anatomy and Treatment Options, Aesthetic Surgery Journal, Volume 32, Issue 4, May 2012, Pages 426–440.
King M. Management of Tyndall Effect. J Clin Aesthet Dermatol. 2016;9(11):E6‐E8.