Under-Eye Hollows and Nasolabial Folds: Aging of the Midface

The full text of my column published in the February 2025 issue of D&PS.

A youthful face typically has an oval outline tapering into a V, whereas an older face tends to widen toward the bottom, like an inverted V. Dr. So-yeon Yi, Korea's first astronaut, studied and published how a Korean astronaut's face changed in microgravity. A characteristically square face became relatively more oval in weightlessness. This illustrates how strongly the sustained effect of gravity contributes to facial aging.

Figure 1. Changes in the face under the influence of gravity.

Why do under-eye hollows, dark circles, and lower-eyelid aging develop?

The under-eye area is one of the features that most strongly influence a person's overall appearance. It is also one of the first places where women, in particular, notice that they are starting to look older. Even men who pay little attention to aging elsewhere are often willing to consider surgery for drooping eyelids and changes beneath the eyes.

The lower eyelid is only about 0.5 mm thick overall. Both upper and lower eyelids undergo pronounced age-related degeneration as dermal collagen and hyaluronic acid decline. The lower lid's vulnerability is largely anatomical. Along with skin aging, changes include stretching of the palpebral ligaments that support the eye horizontally, laxity or excessive tension of the surrounding orbicularis oculi, and stretching of the orbital septum that contains the under-eye fat.

Figure 2. Hallmarks of midface aging include descent of the lid–cheek junction, development of the tear trough, malar fat pad descent, malar festoons, and deepening of the nasolabial fold. Source: https://plasticsurgerykey.com/midface-lift.

Gravity also affects the supporting framework of the eye, making the eyelid more lax. This can be assessed with the snap-back and distraction tests. With age, the ligaments supporting the eyelids loosen and the orbicularis oculi thickens. Lower-eyelid aging involves protruding orbital fat, the pull of retaining ligaments (visible in features such as the tear trough), the eyelid swelling common around the eyes, and orbicularis hypertrophy.

The lower eyelid has three layers: an anterior lamella of skin and orbicularis oculi, a middle lamella formed by the orbital septum, and a posterior lamella of tarsal plate and conjunctiva. The septum arises from the arcus marginalis at the bony orbital rim and attaches to the lower edge of the tarsal plate. Lower-eyelid orbital fat lies behind the septum, while suborbicularis oculi fat (SOOF) lies slightly deeper than the orbital portion of the orbicularis. Relative to the infraorbital nerve, SOOF is prominent centrally and laterally but very thin medially. With age, the lower-eyelid orbicularis and SOOF descend, mainly inferolaterally, contributing to malar bags and festoons. The underlying mechanisms resemble those of upper-eyelid descent: loss of skin collagen, reduced muscle tone, and redistribution of fat. Assessment must also include the medial and lateral canthal ligaments that anchor the orbicularis, along with the retaining ligaments involved in the midcheek groove and tear trough. It should also consider how visible venous blood contributes to dark circles, along with melasma and other melanin-related pigmentation common in this area.

The three-dimensional contour of the lower eyelid is influenced not only by fat and retaining ligaments but also by the abundant lymphatic fluid around the eyes. Bulging caused by fluid accumulation can vary considerably throughout the day. Some patients develop fluctuating periorbital swelling after fat removal for lower-eyelid bags or after fat repositioning, lower blepharoplasty, filler, or fat grafting to correct tear-trough hollows. In these cases, it is important to assess whether the procedure has compressed or obstructed lymphatic drainage around the eye.

The lower eyelid has thin skin and many blood vessels, so hemoglobin often gives the area a dark appearance. Darker areas appear recessed, which means a lower lid darkened by visible vessels can look hollow even when the contour alone does not explain that impression.

Understanding the anatomy behind under-eye hollows

Arteries, veins, and nerves around the eyes often follow the same or closely neighboring routes; the supraorbital and supratrochlear arteries, veins, and nerves are examples. Several recently reported cases of blindness after filler injection around the eyes have renewed attention to vascular connections with the ophthalmic artery and vein or the cavernous sinus. Particular care is needed when injecting filler or fat near the relatively large angular vessels, with the possibility of blindness always kept in mind.

The rich blood supply around the eyes allows relatively rapid healing after surgery or injury, and severe scarring is uncommon. The upper eyelid, however, moves repeatedly with blinking and places tension on the skin. Wounds near the levator can separate and leave more noticeable scars. The lower lid is under less of this strain and rarely scars after surgery. On the other hand, its thin skin and dense underlying vasculature make pigmentation after injury or surgery quite common around the eyes.

Facial fat generally loses volume or descends under gravity with age. In the lower eyelid, however, fat bulges rather than diminishes, creating the impression that its volume has increased. This is not a change in subcutaneous fat of the kind seen elsewhere. Orbital fat behind the orbicularis and orbital septum pushes forward through the weakened septum. There is no subcutaneous fat immediately beneath lower-eyelid skin; the palpebral orbicularis is not distinctly separated from the subcutaneous tissue, and under-eye fat lies beneath the muscle, behind the septum. At the transition to the palpebral portion of the orbicularis, supraorbital fat lies anteriorly and SOOF lies behind the muscle.

The orbicularis retaining ligament, tear-trough ligament, and zygomatic cutaneous ligament are important in the aged appearance of the lower lid. Visible signs in the under-eye area and midface are often described as mounds and grooves. Mounds include lower-lid bulges, malar mounds, and malar fat pads. Grooves include the tear trough, comprising the nasojugal and palpebromalar grooves, the midcheek groove, and the nasolabial fold. Some people are most bothered by a hollow tear trough; others dislike the bulging, descending malar fat pad between the midcheek groove and nasolabial fold. The orbital retaining and zygomatic cutaneous ligaments are among the key structures that define these mounds and grooves.

Figure 3. Anatomical structures at different points along the nasolabial fold.

What are the different types of nasolabial folds?

Four midface muscles involved in smiling lift the nasolabial region, three muscles pull the mouth corners and jawline downward, and one elevates the chin. With age, the mouth corners and jawline tend to descend while the chin becomes more prominent. Deep fat pads form the deepest layer of the nasolabial region. Above them, muscles of facial expression run in several directions. The space beneath the cheekbone is broad, allowing muscles to attach at different angles. Superficial fat lies above the muscles. The principal muscles attaching to the nasolabial region are the levator labii superioris alaeque nasi, levator labii superioris, and zygomaticus major and minor.

The first type of nasolabial fold reflects differences in local tissue volume, particularly a deficit beside the nostril. The canine fossa of the maxilla, which supports this paranasal volume from below, is recessed. Above the fold, nasolabial fat bulges; below it, beside the nasal ala, there is naturally very little superficial fat.

The second type develops as soft tissue descends with age. Upper-lip skin below the fold is relatively firmly attached to the underlying orbicularis oris, so it stretches less. The skin and tissues above the fold are more loosely attached. As the superficial nasolabial fat over the anterior cheek enlarges and descends, it overlaps the firmly attached upper-lip skin. If filler is placed along this type of fold, it may be unable to move downward and instead shift upward. That can make the area above the fold fuller and the fold itself more conspicuous.

The third type arises from muscles originating at the cheekbone that elevate the mouth corner. As they descend and run more superficially, they pull on the skin beneath the lower border of the nasolabial fat. The levator labii superioris alaeque nasi, levator labii superioris, and zygomaticus major and minor are involved.

(To be continued in the next issue)

View the published pages