Tear trough filler: when it helps dark circles, and when to hold back

Four kinds of dark circles

A dark circle often has several causes at once. There are four main families:

• The hollow circle, or tear trough: with age, the bone and fat under the eye lose volume, while ligaments hold the skin in place. A hollow forms, and its shadow darkens the eyes.
• The pigmented circle: the skin itself is darker. Sun, eczema, some medicines (including eye drops) or deposits from the blood can be the cause, sometimes since childhood.
• The vascular circle: the very thin eyelid skin lets the small vessels and the muscle underneath show through, giving a darker, sometimes purplish tint.
• Bags: fat bulging under the eyelid, or fluid building up. Fluid bags are typically worse in the morning or after a salty meal.

The examination: light and skin

Light from above deepens the shadow of a hollow, while light from the front softens it. So I look at your eyes under several kinds of lighting, in addition to the standardised photographs. A colour that persists whatever the light points rather to the skin itself.

I also check the support of the lower eyelid by gently pulling it down: an eyelid that returns slowly to its place indicates laxity.

Tear trough filler: who can benefit?

Hyaluronic acid fills a hollow. It is therefore suited first to the hollow circle, in someone whose skin keeps good firmness and reasonable thickness, without marked bags or swelling. In that case, it can clearly soften the shadow.

A circle that is both hollow and pigmented can also benefit: once the hollow is corrected, light is reflected more evenly. But the colour of the skin itself does not change.

In a randomised trial funded by the gel's manufacturer, among 287 treated people, the improvement persisted at one year in 63.5% of them according to a blinded evaluator; among those who had a new injection at one year, 80% were still improved six months later. Not every gel lists this area in its instructions for use: I will tell you at the consultation where things stand for the one I use.

When I do not offer hyaluronic acid

• Marked fat bags. The more the fat bulges, the more product a narrow area would need, and the poorer the result.
• Puffy eyelids, especially in the morning. Hyaluronic acid attracts water: it can worsen this retention, all the more as it can compress the small lymphatic vessels that drain the area.
• Very thin or very lax skin. Too much product would be needed, and any swelling would show more. A gel placed too superficially can also give a bluish reflection: this is the Tyndall effect.
• A dark circle that is only pigmented or vascular, with no hollow: there is nothing to fill.
• An active cold sore, a flare of acne or rosacea, pregnancy or breastfeeding, or a permanent product already injected in the area.

How I work under the eye

Under the eye, choosing the gel is a compromise. It must absorb little water: a gel that swells a lot may worsen puffiness. Yet soft gels often absorb more water, and experts differ on the preferable firmness: some advise against firm gels, while the trial cited above used one.

The gel is placed deep, in contact with the bone, slowly and in small amounts. An expert consensus recommends at most half a millilitre per side and per session, and waiting about four weeks before adding more, while the gel settles. The check-up around day 15 is therefore mainly for assessment.

Vascular caution is essential. The angular artery and vein run very close by, and the arteries of the face connect with those of the eye. An injection into a vessel can, very rarely, cause skin necrosis or even loss of vision. I use a needle or a blunt-tipped cannula depending on your anatomy, and hyaluronidase and an emergency protocol are always available at the practice. Any visual disturbance after an injection means calling 112.

Recovery is usually simple. In an analysis of 31 studies including more than 2,500 people, swelling and bruising each affected about one person in five; the Tyndall effect remained rare, under 1%.

Other approaches

When the cause lies elsewhere, we talk it through together:

• Fat bags or excess skin: an injection does not correct them; other approaches exist, including eyelid surgery (lower blepharoplasty).
• A pigmented circle: daily sun protection, suitable skincare and, depending on the case, dermatological care.
• Puffiness: look for the cause with your GP, for example an allergy or too much salt.
• In every case, concealer remains the least invasive option.