Fig. 4.5 Prominent eyes with lower eyelid retraction right greater than left

4.3Examination of the Brow and Upper Eyelid Continuum

The forehead, brows, and upper eyelids are the major constituents of the upper face. The assessment of this zone can be subdivided into assessments of skin, rhytids, brows, and the eyelids, but it is imperative to recognize the interrelationships and continuity of these structures [9].

Beginning with a macroscopic assessment, the forehead and scalp are evaluated. The forehead shape, hairline, and hair quality (e.g., thickness) should be inspected. Mild male pattern baldness may respond favorably to pre-trichial incisions, which can lower the hairline. However, it is important to recognize that a mildly elevated hairline is not always objectionable to men. Its manipulation should be discussed before surgery to avoid patient dissatisfaction.

The skin in the periorbital region is vulnerable to aging changes, which should be noted. As the reparative and regenerative mechanisms slow, the skin becomes more fragile and thin. The effects of gravity, sun exposure, environmental factors and genetics accumulate, resulting in damaged collagen cross-linking, and the loss of elasticity and strength. Wrinkles may first appear with facial expressions, but with age and the loss of subcutaneous fat, the dynamic rhytids may become permanent with years of repetitive facial muscle contracture. However, most facial static rhytids occur independent to underlying muscle contracture and may be best treated with resurfacing techniques.

Alternatively, dynamic rhytids and furrows correlate to underlying muscle anatomy. Forehead rhytids develop secondary to facial muscle contracture: one brow elevator (frontalis) and three brow depressor muscles (corrugator supercilii, procerus, orbicularis oculi). The horizontal forehead furrows are due to the vertically oriented frontalis muscle. The vertical lines between the eyebrows, sometimes called “11s,” are due to the corrugator supercilii. Horizontal nasal dorsum rhytids or “bunny lines” are due to the procerus. The orbicularis oculi muscle creates the lateral canthal “crows feet.”

The assessment of dynamic rhytids may include asking the patient to frown, squint, raise the brow, or grimace, which will usually accentuate or deepen the wrinkles or lines. Dynamic rhytids may respond favorably to muscle weakening

Fig. 4.6 Measurement of the degree of prominence with Hertel exophthalmometer

strategies, such as myectomy, myotomy, or chemodenervation with botulinum toxin.

The eyebrow position should be recorded. In males, the brow is typically flat and lies at the level of the supraorbital rim. In females, the brow is arched and lies above the orbital rim, with the highest point at the level of the lateral limbus or lateral canthus. Brow symmetry, or lack thereof, especially the medial and lateral extremes, is important to identify (Fig. 4.7) [10, 11]. Tattooed brows should be noted since they are often placed superior to the actual brow. Browelevating procedures may reposition the tattoos to an unnatural midforehead zone.

Downward gravitational pull and age-related, soft tissue laxity, and bone loss may create brow ptosis, which is diagnosed when the position of the eyebrow is below the supraorbital rim. Frontalis muscle overuse is an additional sign. Prominent horizontal forehead furrows may indicate frontalis muscle compensation (Fig. 4.8). Having patients close their eyes and gently open with the eyebrows relaxed may help identify the resting brow position [12].

The brows may directly affect the upper eyelids. Excess upper eyelid skin, or dermatochalasis, due to brow ptosis, may be especially evident laterally, where the depressor function of the orbicularis is primarily unopposed (Fig. 4.9). Digital elevation of the eyebrows to the correct anatomic position and demonstrating the effect with a mirror or photograph may help patients understand this relationship. Unrecognized brow ptosis may predispose to excessive eyelid skin excision during blepharoplasty and the complications of eyebrow depression or eyelid retraction [13].

Fig. 4.7 Brow and facial asymmetry due to a facial nerve palsy

The upper eyelids, independently and profoundly impact the overall facial appearance and expression. The aging eyelid may create the false impression of fatigue or unhappiness (Fig. 4.10). Droopy, wrinkled, and hooded eyelids can diminish a prior youthful and brighter appearance (Fig. 4.11) [14].

Fig. 4.9 Brow ptosis, prominent horizontal forehead furrows, and excessive upper eyelid folds laterally

Upper eyelid dermatochalasis is commonly caused by reduced collagen and elastic fibers in the dermis. In addition to brow ptosis, loss of integrity of the orbital septum causing fat protrusion, displacement of the orbital portion of the lacrimal gland laterally, and prominent eyebrow fat pads, all contribute to excess eyelid skin or fullness of the upper eyelid fold (Fig. 4.12) [15].

A significant landmark is the eyelid crease, which determines the position of the skin fold. The crease is formed by the fusion of fibers from the levator aponeurosis into the overlying orbicularis muscle and dermis. In non-Asians,

Fig. 4.10 Tired and unhappy appearance related to excess upper eyelid skin

the crease is typically 8–10 mm above the eyelid margin in females and 6–8 mm in males. The space between the margin and the crease has been referred to as the “eyeshadow space” or tarsal platform, is often desirable, and may be feminizing, especially in non-Asians (Fig. 4.13).

In the Asian eyelid, the crease may be significantly lower or even absent due to a lower inferior septal insertion and

orbital fat pad obliteration of the crease-forming levator fibers. It is important to maintain the low crease configuration in the Asian eyelid since an unnaturally high crease may make obvious that the patient had surgery and overly “westernize” the appearance.

Asymmetry, elevation, or loss of the eyelid crease may signify levator aponeurosis pathology. Stretching or dehiscence of the levator aponeurosis may result in a high eyelid crease (Fig. 4.14). Volume depletion from fat atrophy or retraction of the central preaponeurotic fat pad may exacerbate the deep, hollow, upper eyelid sulcus from ptosis or enophthalmos.

Critical measurements in the assessment of upper eyelid ptosis are the vertical palpebral fissure, margin-to-reflex distance one (MRD1), and especially levator function. Evaluation should be conducted in primary gaze, with the frontalis muscle relaxed and the brow in a fixed position.

The average vertical palpebral fissure is approximately 10 mm. The vertical excursion of the eyelid (ask the patient to look down and then up), determines the levator function. The normal range is between 12 and 18 mm. It is important to negate the effect of the frontalis muscle with a thumb or digit, when assessing the levator function. The correct procedure in treating eyelid ptosis depends critically on levator function.

The margin-to-reflex distance (MRD1) is the space in millimeter between the central corneal light reflex and the upper eyelid margin, and typically ranges between 4 and 4.5 mm. A diminished MRD1 typically signifies ptosis of the upper eyelid, whereas an elevated MRD1 indicates eyelid retraction (Fig. 4.15). Upper eyelid retraction is most commonly a manifestation of thyroid-associated ophthalmopathy, but may be secondary to a host of other causes, including high myopia, buphthalmos, facial nerve palsy, or trauma.