The eyelid can be considered to have three lamellae. The inner layer (posterior lamella) consists of the conjunctiva lining the globe and inner eyelid, the tarsal plates, (providing structural support) the medial and lateral canthal tendons, the retractor muscles, and the capsulopalpebral fascia. The middle layer includes the orbital septum and the pre- and postseptal fat compartments. The outer lamella (anterior lamella) consists of skin and orbicularis oculi. Knowledge of eyelid anatomy is key when considering reconstructive or aesthetic surgery in this area. The eyelid skin is the thinnest on the body, typically 1 mm, but this can range from as little as 0.3–1.3 mL. Postauricular skin is usually at least 1-mm thick but still can be a useful donor site for eyelid reconstruction where skin grafts are required. Hypertrophic scarring is seen typically in burns, sites of delayed healing, or undue tension on wounds. In contrast, surgery to the eyelids usually results in very high-quality scars.1,2
2. McCord CD, Codner MA, eds. Eyelid & Periorbital Surgery. St Louis: Quality Medical Publishing; 2008 The orbicularis oculi acts as a sphincter around the eye and has three components (not two): orbital, pretarsal, and preseptal. Orbital fibers overlie the orbital rim and are responsible for voluntary closure of the eye such as winking and forceful squeezing. Pretarsal fibers overlie the tarsal plate and are responsible for involuntary oculi receive innervation from the facial nerve (CN VII) via its deep surface, as do most of the facial mimetic muscles. Only three of them are innervated via their superficial surfaces: the buccinator, levator anguli oris, and mentalis.1,2
The eyelids contain preseptal and postseptal fat. The preseptal fat lies between the orbicularis oculi and the orbital septum. This can contribute to the aging process as it moves downward. In the upper eyelid it is known as the retro-orbicularis oculi fat (ROOF) and in the lower eyelid it is known as the suborbicularis oculi fat (SOOF). Behind the orbital septum there are further fat compartments. There are two in the upper eyelid (medial and central) which are separated by the trochlea and superior oblique extraocular muscles. There is no lateral fat compartment because this space is occupied by the lacrimal gland. In the lower eyelid there are three compartments (medial, central, and lateral). The medial and central fat pads are separated by the inferior oblique extraocular muscle. The tarsal plate is a dense cartilaginous structure located adjacent to the eyelid margin and provides structural support and rigidity to the eyelids. The tarsal plate of the upper eyelid has a greater vertical height (10 mm) than that of the lower eyelid (4 mm), but both have similar widths. The tarsus is separated from the orbital rim by the orbital septum. The superior margin of the upper eyelid tarsus is the attachment for Müller’s muscle and the levator aponeurosis. The bulbar portion of the conjunctiva lines the sclera, and the palpebral portion lines the inner surface of the eyelids. The two join at the superior and inferior fornices.1,2
The levator palpebrae superioris (LPS) is the primary upper eyelid elevator and is supported by Müller’s muscle. The LPS is innervated by CN III and originates from the lesser wing of sphenoid (not greater) to insert the superior tarsus and dermis to create the supratarsal crease. It broadens as an aponeurosis at Whitnall’s ligament which redirects the horizontal pull to a vertical one in order to elevate the eyelid effectively. Müller’s muscle is innervated by the sympathetic nervous system, which is carried along with the ophthalmic nerve through the cavernous sinus. The fibers originate from the superior cervical ganglion. This muscle arises from the inferior surface of the LPS and inserts into the superior edge of the tarsal plate. Loss of Müller’s muscle function results in 2–3 mm of ptosis. The lower eyelid also has retractors and these are the capsulopalpebral fascia and inferior tarsal muscle. These are analogous to the LPS and Müller’s muscle, respectively.1
Tears produced by the lacrimal gland enter the external surface of the globe via the superior fornix. The tear film then coats the surface of the eye to provide lubrication, reduce risk of infection, mechanically remove foreign bodies, and increase the refractive power of incoming light. Following this, the normal passage of tears is to enter the lacrimal sac via the lacrimal puncta along the upper and lower eyelid margins. These puncta open into the superior and inferior canaliculi respectively. They join together to form the common canaliculus and empty into the lacrimal sac through the valve of Rosenmüller. From here the lacrimal sac empties into the nasolacrimal duct to drain tears into the nasal cavity. In order for tears to move from the eye into the lacrimal sac, there needs to be a pressure difference with negative pressure within the lacrimal sac relative to the eye. Eye closure is required to create this negative pressure. On eye closure, the sac fills and then when the eyes reopen, the tears are expelled into the nasolacrimal duct. Therefore, the primary reason why patients with facial palsy have epiphora is that the negative pressure mechanism for filling the lacrimal sac is impaired due to the loss of innervation to the orbicularis oculi (usually innervated by CN VII) and consequent problems with reduced blinking. The lacrimal gland is not innervated by the facial nerve so is unaffected. It is innervated by the lacrimal nerve from CN V and has parasympathetic and sympathetic innervation from the pterygopalatine ganglion and superior cervical ganglion, respectively. The valve of Hesner is found between the nasolacrimal duct opening and the nose. It is a mechanical valve that stops reflux of air or nasal contents up the duct system.1
Blood supply contributions to the eyelid include the following: Facial artery: This vessel forms the angular, lateral nasal, and inferior medial palpebral arteries. Transverse facial artery: This vessel forms the zygomaticofacial and inferior palpebral arteries. Superficial temporal artery: This vessel forms the superior medial palpebral artery (peripheral arcade). Ophthalmic artery: This vessel forms the lacrimal, supraorbital, medial palpebral, and dorsal nasal vessels. The upper eyelids are primarily supplied by branches of the ophthalmic artery (the first branch of the internal carotid). The lower eyelids are mainly supplied by branches of the facial artery (a branch of the external carotid). The angular artery is a continuation of the facial artery as it passes lateral to the nose. (This later becomes the lateral nasal artery, which anastomoses with the dorsal nasal artery from the ophthalmic artery.) Both marginal and peripheral arcades supply the eyelids (Fig. 40.1).1
When considering eyelid reconstruction, both size and depth of defect must be taken into account as this will affect reconstruction choice. Also during reconstruction, it is important to ensure satisfactory anchoring of the canthi or temporary closure of the eyelid margin with a “Frost stitch.” In general, defects of up to 25 or 30% can usually be closed directly, but this depends on individual patient factors such as eyelid laxity, tissue quality, and age. In some elderly patients, it is possible to close defects of up to 40% directly. Defects between 25 and 50% can often be closed primarily with the addition of a lateral canthotomy and cantholysis (release of the lateral canthal tendon), but defects larger than this will still usually require additional importation of tissue from the opposite eyelid or adjacent regions such as the cheek, forehead, or temple. Although there are techniques that borrow tissue from the upper eyelid to reconstruct the lower eyelid, these should be performed with caution because the upper eyelid is a dynamic structure that contributes significantly to eyelid function.1–4
There are a number of different approaches for reconstruction of conjunctival defects, depending on the size and whether the tarsus is also involved. Where possible it is preferable to reconstruct isolated conjunctival defects by advancing adjacent conjunctival tissue. In cases where this is not possible, grafts may be harvested from the buccal or nasal mucosa, and of these, nasal mucosa is generally preferred because there is less secondary contraction. Skin grafts are contraindicated for corneal reconstruction because they irritate the cornea. In contrast, for upper and lower eyelid skin reconstruction, full-thickness skin grafts from the contralateral upper eyelid work well and ensure good thickness and color match. Use of a lower eyelid graft to reconstruct the upper would, however, Fig. 40.1 Arterial supply to the eyelid. (Adapted from McCord CD Jr, Codner MA. Eyelid & Periorbital Surgery. St Louis: Quality Medical Publishing, 2008.) Lacrimal artery Superficial temporal artery Zygomaticofacial artery Infraobital artery Facial artery Inferior palpebral artery Angular artery Lateral nasal artery Dorsal nasal artery Supratrochlear artery Supraorbital artery Inferior medial palpebral artery Transverse facial artery Superior medical palpebral artery (peripheral arcade) Superior medical palpebral artery (Marginal arcade) not be recommended as this may result in development of ectropion. Several options exist for reconstruction of the tarsal plate. These include palatal mucosa grafts, autologous cartilage, and allografts such as AlloDermTM.1–4
The Tenzel semicircular flap is a single-stage, laterally based myocutaneous flap technique that is combined with lateral canthotomy and cantholysis to reconstruct upper eyelid defects.1,2 The Cutler-Beard flap is a two-stage flap sharing technique used for full-thickness upper eyelid defect reconstruction. It involves advancement of a full-thickness lower eyelid flap that is passed under the lower eyelid margin and sutured into the upper eyelid defect. Division is usually performed at 3–6 weeks.3 A Fricke flap is a type of transposition (not advancement) flap that is also known as a temporal forehead flap. It can be used to reconstruct partial-thickness upper or lower eyelid defects; however, the tissues of the brow from which it is harvested are different to the eyelid and these flaps tend to be rather bulky for eyelid reconstruction.4 The paramedian forehead flap is primarily used for nasal reconstruction, but may be used in select cases of eyelid reconstruction where extensive defects are present. It can be useful for combined eyelid and nasal defects but is not limited purely to this. The Hughes flap is a tarsoconjuncival flap used in two stages to reconstruct the lower eyelid with the upper eyelid as a donor site. The flap is raised and inset into the defect to reconstruct the posterior lamella and covered with a full-thickness skin graft to reconstruct the anterior lamella (Fig. 40.2).5 Fig. 40.2 The semicircular flap, or Tenzel flap, is used for defects involving up to 60% of the upper eyelid. Lateral canthotomy is required to rotate the flap. (Adapted from DiFrancesco LM, Codner MA, McCord CD Jr. Upper eyelid reconstruction. Plast Reconstr Surg 114:98e–107e, 2004.)
plate are intact and most of the orbicularis oculi has been preserved. The general principles for eyelid reconstruction follow the principles common to most reconstructions: analyze the defect site and tissue structures involved, then reconstruct, replacing like with like where possible. The selection of a technique for eyelid reconstruction will therefore depend on the site; for example, upper versus lower eyelid, and the width, height, and depth of the defect. Partial-thickness defects such as this anterior lamella case can be reconstructed with a full-thickness skin graft, providing there is a well-vascularized recipient bed such as orbicularis oculi. A full-thickness graft is preferable to a split-thickness graft because there will be less secondary contraction which can risk development of ectropion. Many patients, particularly the elderly, will have an excess of upper eyelid skin and this can make a good graft donor site as the skin is thin and a good color match for the contralateral eyelid. Symmetry can be achieved between the sides with such an approach by taking a slightly undersized graft, and the donor and recipient sites are often difficult to identify in the longer term. The use of a graft from behind or just in front of the ear is a good alternative where there is insufficient upper eyelid skin as this also has a suitable color and thickness match. However, caution should be taken when using the ipsilateral preauricular area in case a local flap is later required from this side. The Fricke flap could be used in this case, but would provide tissue that will be unnecessarily thick. Primary closure would have been a good option if the defect was less tall, that is, up to 1 cm, but in this scenario, direct closure would likely result in lagophthalmos.1,2
The Cutler-Beard flap is indicated in reconstruction of full-thickness defects of the upper eyelid using the ipsilateral lower eyelid as a donor site. It is a two-stage procedure that harvests full-thickness tissue from the lower eyelid. In the first stage, the flap is developed below the inferior tarsus and passed beneath the lower eyelid margin into the upper eyelid defect. It the second stage, the flap is divided and inset. As the tarsus is not harvested, eyelid support will need to be provided by a cartilage graft inset between the conjunctiva and muscle layers. However, this flap will provide missing conjunctiva, muscle, and skin to the upper eyelid. Although each of the other flaps (except the Tripier) can be used to reconstruct full-thickness upper eyelid defects, each will need conjunctival replacement with a mucosal graft as well as graft for the missing tarsus. The forehead and Fricke flaps will be unduly thick for this reconstruction and therefore less than ideal. The Tripier flap is a myocutaneous flap used for partial-thickness defect reconstruction in the lower eyelid. It is harvested from the ipsilateral upper eyelid, so would be unhelpful in this case (Fig. 40.3).1,2 Fig. 40.3 The Cutler-Beard flap is used for total upper eyelid reconstruction. The flap is a biplanar flap passed beneath the lower eyelid margin. (Adapted from DiFrancesco LM, Codner MA, McCord CD Jr. Upper eyelid reconstruction. Plast Reconstr Surg 114:98e–107e, 2004.)
This represents a complex defect for reconstruction with all three lamellae deficient. The Hughes tarsoconjunctival flap represents a good option here because it provides both tarsus and conjunctiva for reconstruction of the posterior lamella and full-thickness graft can be applied to reconstruct the anterior lamella. The Tenzel flap is useful to reconstruct defects of the anterior lamella of up to 60% but will need a mucosal graft and cartilage graft for reconstruction of the posterior lamella. Lateral canthotomy and cantholysis are used for smaller defects. The paramedian forehead flap could in principle be used to reconstruct the outer lamella if combined with mucosa and tarsal reconstruction, but it is more normally indicated in upper eyelid and nasal reconstruction. The Mustarde cheek rotation flap is an ideal choice for reconstructing larger anterior lamella defects of the upper eyelid. However, it would not require a skin graft, but would again need a mucosal graft for the conjunctiva (Fig. 40.4).1–3 Fig. 40.4 Hughes tarsoconjunctival flap. A, The flap is elevated from the everted upper eyelid, closer to the margin than the free tarsoconjunctival graft. At least 4 mm of tarsus at the margin should be spared to preserve stability of the upper eyelid. The original Hughes procedure split the upper eyelid at the margin, which produced upper eyelid trichiasis. B, The flap should be as free of Müller’s muscle as possible and sutured into the posterior lamellar defect. If tarsus remains on either edge, edge-to-edge approximation is needed. If the defect is toward the canthus, canthal fixation is needed. C, Since the tarsoconjunctival flap from the upper eyelid includes its own blood supply, a full-thickness skin graft can be used on its surface. A blepharoplasty or cheek-lift myocutaneous flap can be used if enough tissue is available. Separation usually takes place at 3 weeks, when the flap gains a new blood supply. Separation may be needed later if a full-thickness skin graft is used. (From McCord CD Jr, Codner MA. Eyelid & Periorbital Surgery. St Louis: Quality Medical Publishing, 2008.) A B C Tarsus