Eyebrows | ophthalmologyrounds

The Eyebrow: Basic Anatomy and Treatment of Abnormalities

By Navdeep Nijhawan, MD, FRCSC

Many eye care professionals tend to ignore or have limited understanding of the brow and its function in total ocular health. They see this as mainly a cosmetic concern that is insignificant in the overall ocular health of the individual. Confusion as to what truly is brow ptosis versus other abnormalities of the upper face and eyelids, such as dermatochalasis and blepharoptosis, adds to the overall incorrect management and dissatisfaction of these patients. This issue of Ophthalmology Rounds looks at the anatomy of the brow region and what is considered an “ideal brow,” the pathologies that can exist, and the medical and surgical treatment options.

The eyebrows are important factors in facial expression and mood and differ significantly between males and females. Female eyebrows are arched with the highest point above the lateral canthal angle and well above the orbital rim, and the male eyebrow is flat and full and is at the orbital rim (Figure 1).[1]

Figure 1: Differences between female (left) and male (right) brow.
Note higher arch in female brow.

There is significant debate as to what constitutes an “ideal” brow. In 1974 Westmore described characteristics of an “ideal” brow arch.[2] The description has been redefined by numerous authors but essentially the ideal brow is “gently curved with the apex aligned at the corneal limbus, the medial brow edge should begin on the same vertical line as the lateral nasal ala and the inner canthus and the lateral brow edge should end at the oblique line described by the lateral nasal alae and lateral canthus. The male brow is similar in contour but straighter and lower” (Figure 2).[3]

Figure 2: Westmore’s concept of ideal brow position showing high point of arch at lateral limbus and position of head and tail of brow.

Reproduced with permission from Branham G and Holds JB. Facial Plast Surg Clin North Am. 2015;23(2):117-127.
Copyright © 2015, Elsevier

Pop culture can also impact what is considered aesthetically acceptable. In western society individuals younger than 30 years prefer brows at a lower position as opposed to older individuals who have a preference for higher brows. Much of this is a reflection of what current fashion trends consider as more aesthetically pleasing. Fashion magazines have recently glamorized thick, full, low-set brows as opposed to high arching brows that were considered more pleasing 40–50 years ago.[3]

Anatomy

In order to appreciate brow pathology, eye care professionals need to have a clear understanding of brow and forehead anatomy. The brow and forehead constitute the area of the face from just below the brow hairs extending up to the hairline. The eyebrow consists of 3 anatomical parts – namely the head, body, and tail – and is part of the scalp.[1] The elevator of the brow is the frontalis muscle. Horizontal forehead wrinkles are also a result of frontalis action. The frontalis muscle is innervated by the temporal branch of the facial nerve. The depressors of the eyebrow are the orbital portion of the orbicularis oculi, corrugator supercilii, and procerus muscles. These muscles are also innervated by the facial nerve.[4-6] Many patients who have suffered a facial palsy or trauma will have diminished or absent brow and eyelid function. The typically have brow droop and poor eyelid closure.[1]

One of the most common signs of the aging face is brow droop (brow ptosis). It is not unusual for patients to come their eye care professional requesting eyelid surgery for their “droopy eyelid” when in fact their main issue is brow ptosis.

There remains confusion among eye care providers about the 3 different facial etiologies of the generic term “droopy eyelids” that patients will use to describe their facial and eyelid change. This often leads to further confusion for the patient as to what surgery or surgeries are recommended and what procedures are or are not insured by their provincial health plans. Eye care professionals need to be able to differentiate between blepharoptosis, dermatochalasis, and brow ptosis.

Blepharoptosis, also known as ptosis, refers to an abnormality of the levator muscle, its aponeurosis or innervations that causes a drop in the overall lid height. Treatment for blepharoptosis in general is surgical manipulation of the levator aponeurosis or muscle (Figure 3).

Figure 3: Bilateral blepharoptosis.

Dermatochalasis refers to the redundant skin/fat that is seen in the upper and lower eyelids. The mainstay of treatment is blepharoplasty (Figure 4).

Figure 4: Severe dermatochalasis with mild brow ptosis on the right side in this elderly male

Brow ptosis refers to a descent of the brow to a lower position than what is considered normal or aesthetically appealing. Management of brow ptosis is described further in this article (Figures 5–7).

Figure 5: Temporal brow ptosis, right greater than left, causing fullness in the upper lid. Note the low position of the brow in this middle-age woman as compared to a younger woman. Patient also has coexisting dermatochalasis, which can aggravate the appearance of “eyelid droop.”

Figure 6: Bilateral brow ptosis in this middle-aged male

Figure 7: Left brow ptosis secondary to facial palsy. Note the absence of forehead wrinkles

In many instances individuals will have coexisting conditions of brow ptosis, dermatochalasis, and blepharoptosis, and patients will need to have multiple procedures to address all the issues.[7] In assessing a patient’s upper eyelids they should be viewed in contiguity with the other structures of the upper face including the eyebrows and forehead.3 Several authors have described this anatomic unit as the brow-lid continuum to highlight the significance of the critical interplay between the eyelid and eyebrow.[3,8]

In most instances of patients with brow ptosis the aging appearance of their “drooping eyelids” is their paramount concern; however, some will also note that they are suffering from superior visual field loss, fatigue, and difficulty with activities of daily living such as driving and reading. The literature also suggests that visual field loss can also increase the risk of falling in the elderly.[7] Furthermore, eye care specialists will invariably have to manage a subset of patients with functional brow ptosis who have had paralysis resulting in loss of function of their upper face. Their concerns are rarely cosmetic and more functional in nature.

Brow ptosis is typically a function of the aging face. As the face ages and the forehead loses its elasticity, the brow assumes a lower position and crowds the orbit region with resulting skin redundancy in the upper eyelid. This is also accentuated by fine lines and deeper creases in the forehead due to repetitive contraction of the frontalis muscle, corrugator, and procerus.[6]

As noted above, functional brow ptosis is also seen in patients with a facial palsy or trauma.[9] Many of the management options for brow ptosis are similar whether the brow ptosis is due to a pathological process or cosmetic in nature.

Assessment of Brow Ptosis

Assessment of a patient with brow ptosis involves obtaining a full medical and surgical history, quantifying the lid abnormality, and then offering options for repair.

History

As with any surgical procedure, part of the history also includes questioning about the patient’s general health, including medical comorbidities and medications. Notably, physicians need to determine if the patient is taking anticoagulants and specifically what the medical indications are for these medications. A decision on how to work with anticoagulants (either stopping them or reducing the dose) will need to be made in conjunction with the patient and their primary-care physician. The preference is to individualize the anticoagulation routine perioperatively. Due to the extensive blood supply of the forehead, surgeons should be cognizant of maintaining excellent hemostasis during any surgeries involving the forehead and eyelids.

All patients undergoing ptosis repair or blepharoplasty will also need to be questioned about their dry eye history. If the patient has poorly controlled dry eyes preoperatively, one can reasonably assume that their dry eyes will be aggravated postoperatively. Proper management of dry eye issues should be addressed preoperatively with medical management, including adequate lubrication.

Physicians should also make every effort to have a frank discussion with patients about their expectations with brow surgery. Spending some time preoperatively in having this conversation will ensure that the patient has realistic expectations and will save the physician unnecessary aggravation postoperatively if the expectations of the patient are inconsistent with what the physician can offer.

Physical examination

The physical examination for patients with brow abnormalities includes a complete anterior segment examination comprising visual acuity and assessment of eyelid parameters such as marginal reflex distance, interpalpebral height, levator function, lid crease height, and lagophthalmos. The cornea status should also be noted, including evidence of dry eyes, corneal sensation, and corneal scarring. While not universally adopted, some physicians will also assess tear production with Schirmer testing.

Quantification of brow abnormalities can prove to be challenging. There is no universally accepted measurement for determining brow abnormalities. Different measurements have been proposed, including indices looking at bony architecture such as forehead width, height, and orbital height. Unfortunately, these measures do not adequately address the overlying soft tissues abnormalities.[10] Lew and Goldberg proposed the concept of tarsal platform show and brow fat span as methods of understanding the relationship between the eyelid and brow. Brow fat span is the measurement from the top of the eyebrow cilia to the top of the visible tarsal plate. The tarsal platform show is a measurement from the superior aspect of the visible tarsal plate to the lid margin. The authors believe that the tarsal platform show is the most important measurement to treat as this will ensure most consistent eyelid symmetry.[2,11] Oestreicher and Hurwitz have developed a clear plastic facemask that can be used to measure eyebrow position; however, this is not currently commercially available.[10] Due to the variable nature of brow abnormalities and inconsistent measurements it is prudent for all operating surgeons to document the abnormality with facial photos prior to operating.[8]

Once a complete history and physical examination has been performed surgeons should carefully discuss all of the available options to manage the patient’s abnormalities. While surgical management is the cornerstone of treatment, several medical options are available to deal with the aesthetic issues surrounding brow ptosis and forehead lines and creases. To the detriment of the patient, many clinicians skip or gloss over these quick and simple medical options in favour of surgical management. Some patients will need both for the best aesthetic results.

Management

Medical management

In the realm of cosmetic surgery treating the underlying skin is an important first step. Perform a thorough assessment of the patient’s skin with ongoing skin care, including moisturizers and sun protection such as sunglasses and wide-brimmed hats. Educate the patient about the negative impact of sun exposure. Treatments such as topical retinoids, hydroquinone, alpha hydroxyl acids, and laser resurfacing are important tools in the armamentarium of the cosmetic surgeon in addressing sun-induced damage.[12] Patients should also be counselled about the negative effects of other lifestyle choices such as smoking on facial aging.

Medical management of brow abnormalities using injectables fall into 2 categories: botulinum toxin (BTX) and fillers.

BTX has been used for decades to address facial rhytids. It is a neurotoxin that causes partial temporary paralysis of facial muscles depending on the site of injection.[13] Depending on placement of BTX one can address many of the cosmetic concerns of the brow. The deep glabellar and procerus dynamic furrows in the central brow are the lines that usually give the facial appearance that the patient is angry, worried, or unhappy, and BTX injections are very effective in treating them. BTX injection into the orbital portion of the orbicularis laterally will paralyze the depressor of the lateral brow and can elevate the lateral brow, giving the patient a “medical” brow lift. While the effect is temporary, many patients are satisfied with this procedure in hopes of avoiding surgery. Injection into the horizontal furrows of the frontalis muscle will reduce the dynamic rhytids in the upper/central forehead. The frontalis muscle is a brow elevator so one must be cautious in balancing the amount of BTX injected in the frontalis versus the depressors of the brow (orbicularis oculi, glabellar, and procerus) to ensure that the brows appear balanced and not asymmetric.

All patients who are considering surgical brow correction, blepharoptosis repair and/or blepharoplasty should be asked about recent BTX use in the forehead as this can impact the final outcome of any lid correction.

Reversible hyaluronic acid gel fillers have an important role in addressing deep static furrows in the forehead, glabellar, and procerus region.[12] Many of these fillers are used in combination with BTX to address the deep furrows of the forehead. Irreversible fillers are also available; however, they generally have a more limited role in the periorbital area.

Surgical management

A multitude of surgical approaches may be considered to deal with brow and forehead ptosis. These include transeyelid browplasty, direct, midforehead, coronal and endoscopic.[1,4]

Direct/temporal direct browplasty

Perhaps the simplest technique is the direct browplasty, which involves direct excision of skin and orbicularis above the brow. With this approach one can perform an excision immediately above the entire brow or more temporally if the temporal brow is lower. One has to be careful not to advance the incision too medially as there is risk of damage to the supraorbital nerve. Disadvantages of this approach include a prominent scar, feminization of the temporal brow (an issue with some males), and an inability to treat higher (forehead) and medial (glabellar) furrows. Direct browplasty is very useful for brow paralysis and asymmetric brows but is not ideal for cosmetic patients due to a visible scar.[1,4,9,14]

Transeyelid (transblepharoplasty) browplasty

For combined approaches where the patient is also having blepharoplasty and/or blepharoptosis repair, the transeyelid or transblepharoplasty browplasty is a reasonable option to create a small amount of lift. The scar is hidden in the blepharoplasty incision and it will only treat a mild amount of brow ptosis. Using the lid crease incision the lateral brow is undermined. The frontal periosteum is exposed and the brow is fixed to the periosteum above the orbital rim.[1,9]

Midforehead lift

Midforehead lifts work very well in male patients with deep furrows and receding hairlines. The deep furrows are able to hide the scars of the midforehead lift.[4,14] Nerad described a technique of staggering the incisions across the forehead to address the glabellar region.[1] The excision of the forehead skin and subcutaneous tissue can be closed directly or the surgeon can suspend the brow with sutures.

Coronal lift

Coronal brow lift remains a very effective procedure for the treatment of brow ptosis and for forehead and glabellar furrows.1 The incision can be pretrichial or posttrichial (ie, in front of or behind the hairline). The principal patient complaints include a prominent scar in the scalp and scalp numbness. Other issues include alopecia, skin necrosis, and eyelid and eyebrow asymmetry.[14] Coronal brow lift is not recommended for most women with a high hairline or men with male pattern baldness.[4]

In recent years an increasing number of patients seeking cosmetic improvement in their brows have sought endoscopic forehead lifts due to the perception that coronal approaches lead to unsightly scars and that endoscopic approaches have less noticeable scars and fewer overall issues. In a review of more than 1000 coronal lift procedures one group found more than 98% satisfaction among patients and would undergo the procedure again.[4] Studies like this validate the effectiveness and utility of the coronal brow lift in the management of brow ptosis.

Endoscopic forehead lift

Due to the issues some surgeons and patients have experienced with coronal brow lifts there has been a concerted push towards endoscopic brow lift. As noted previously, not every patient requires a complex procedure and many have satisfactory results with simpler techniques.[15] Significant advantages of endoscopic forehead lift include better maintenance of sensory nerve function, lower rate of alopecia, minimal elevation of the hairline, ability to perform the procedure on bald patients, and quicker recovery.[16] The basic procedure involves making multiple incisions along the superior brow and scalp, release of the periosteal fixations along the entire brow and forehead region using endoscopic equipment, weakening of the depressors, and fixation of the brow.[17] Common complications include inadequate lift, asymmetry, damage to the frontal branch of the facial nerve, hematoma formation, and localized alopecia.

Conclusion

Brow ptosis can have a significant impact in the appearance of the upper face and periocular region.
Eye care professionals need to be able to recognize this distinct entity from other cause of “droopy eyelids”, and understand the treatment options to better guide their patients in ensuring they receive the most appropriate care.

Dr. Nijhawan is a Clinical Assistant Professor of Ophthalmology, University of Toronto and McMaster University, and Vice-Chair, Eye Physicians and Surgeons of Ontario, Toronto, Ontario.

References:

Nerad JA. In: Krachmer JH (ed.). Oculoplastic Surgery: The Requisites in Ophthalmology. Mosby: London (UK); 2001.
Fitzgerald R. Contemporary concepts in brow and eyelid aging. Clin Plast Surg. 2013;40(1):21-42.
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Angelos PC, Stallworth CL, Wang TD. Forehead lifting: state of the art. Facial Plast Surg. 2011;27(1):50-57.
Branham G, Holds JB. Brow/upper lid anatomy, aging and aesthetic analysis. Facial Plast Surg Clin North Am. 2015;23(2):117-127.
Putterman AM. Cosmetic Oculoplastic Surgery: Eyelid, Forehead, and Facial Techniques, 3rd ed. W.B. Saunders: Philadelphia (PA); 1999.
American Society of Ophthalmic Plastic and Reconstructive Surgery. White Paper on Functional Blepharoplasty, Blepharoptosis, and Brow Ptosis Repair. January 15, 2015. Available to ASOPRS members at: http://www.asoprs.org.
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Romo T,3rd, Yalamanchili H. Endoscopic forehead lifting. Dermatol Clin. 2005;23(3):457,67, vi.
Holck DE, Ng JD, Wiseman JB, Foster JA. The endoscopic browlift for forehead rejuvenation. Semin Ophthalmol. 1998;13(3):149-157.