1255

INTRODUCTIONThe eyelids serve a vital function by protecting the globe. They provide fundamental elements of the precorneal tear film and help distribute tears evenly over the surface of the eye. The eyelids collect tears and propel them to the medial canthus, where they enter the lacrimal drain-age system. The eyelashes sweep airborne particles from the front of the eye. Constant voluntary and reflex movements of the eyelids protect the cornea from injury and glare. Any esthetic or reconstructive surgery on the eyelids requires a thorough knowledge of eyelid anatomy.1,2

ANATOMY OF THE EYELIDSIn young adults the interpalpebral fissure measures 10–11 mm verti-cally. With advancing age this decreases to only about 8–10 mm. The horizontal length of the fissure is 30–31 mm. The upper and lower eyelids meet at an angle of approximately 60° medially and laterally. In primary position, the upper eyelid margin lies at the superior corneal limbus in children and 1.5–2 mm below it in adults. The lower eyelid margin rests at the inferior corneal limbus.

The margin is covered by cutaneous epithelium and eyelashes ante-riorly; and conjunctiva with meibomian gland openings posteriorly.

Orbicularis MuscleThe orbicularis oculi is a complex striated muscle sheet that lies just below the skin. It is divided anatomically into three contiguous parts (Fig. 12-1-1): orbital, preseptal, and pretarsal.3

The orbital portion overlies the bony orbital rims. It arises from insertions on the frontal process of the maxillary bone, the orbital proc-ess of the frontal bone, and the common medial canthal tendon. Its fibers pass around the orbital rim to form a continuous ellipse.

The palpebral portion of the orbicularis muscle overlies the mobile eyelid from the orbital rims to the eyelid margins. The muscle fibers sweep circumferentially around each eyelid as a half ellipse, fixed medi-ally and laterally at the canthal tendons. It is further divided topo-graphically into the preseptal and pretarsal orbicularis.

The preseptal portion of the muscle is positioned over the orbital septum in both upper and lower eyelids. Its fibers originate perpendicu-larly along the upper and lower borders of the medial canthal tendon. Fibers arc around the eyelids and insert along the lateral horizontal raphe. The pretarsal portion of the muscle overlies the tarsal plates. Contraction of these fibers aids in the lacrimal pump mechanism.4 Medially, the deep heads of the pretarsal fibers fuse to form a promi-nent bundle of fibers, Horner’s muscle, that runs behind the posterior limb of the canthal tendon. It inserts onto the posterior lacrimal crest. Horner’s muscle helps maintain the posterior position of the canthal angle and may aid in the lacrimal pump mechanism.5

Orbital SeptumThe orbital septum is a thin, fibrous, multilayered membrane that begins anatomically at the arcus marginalis along the orbital rim. Dis-tal fibers merge into the anterior surface of the levator aponeurosis (Fig. 12-1-2).6 The point of insertion usually is about 3–5 mm above the

Jonathan J. Dutton 12.1Clinical Anatomy of the Eyelids

SECTION 1 Orbital Anatomy and Imaging

PART 12 ORBIT AND OCULOPLASTICS

Definition: The eyelids are mobile, flexible, multilamellar structures that cover the globe anteriorly.

Key features■ The eyelids provide protection from desiccation and airborne

foreign matter.■ The eyelids anatomically contain both superficial

musculocutaneous elements anteriorly and orbital components posteriorly.

Fig. 12-1-1 Orbicularis and frontalis muscles. (Adapted with permission from Dutton JJ. Atlas of clinical and surgical orbital anatomy. London: Elsevier Saunders; 2011. p. 153.

ORBICULARIS MUSCLE – ORBITAL, PRESEPTAL, AND PRETARSAL PORTIONS

frontalis muscle

procerus muscle

orbital portionof orbicularismuscle

superiorpreseptal portionof orbicularismuscle

superiorpretarsal portionof orbicularismuscle

lateral horizontalraphe

anterior armof medialcanthal tendon

Fig. 12-1-2 Orbital septum. (Adapted with permission from Dutton JJ. Atlas of clinical and surgical orbital anatomy. London: Elsevier Saunders; 2011. p. 149.

levatoraponeurosis

anteriorlayer

posteriorlayer

arcusmarginalis

superiororbitalseptum

inferior orbitalseptum

ORBITAL SEPTUM

intermediatelayer

12

1256

ORBIT A

ND

OCU

LOPLA

STICS

plate. From this junction, a common fascial sheet continues upward and inserts onto the lower border of the tarsus.

Sympathetic Accessory RetractorsSmooth muscles innervated by the sympathetic nervous system are present in both the upper and lower eyelids and serve as accessory retractors.16 In the upper eyelid, the supratarsal muscle of Müller origi-nates abruptly from the undersurface of the levator muscle just anterior to Whitnall’s ligament.17 It runs downward, posterior to the levator aponeurosis and inserts onto the anterior edge of the superior tarsal border. In the lower eyelid, the sympathetic muscle is not as well defined. Fibers run behind the capsulopalpebral fascia to insert 2–5 mm below the tarsus.18

Tarsal PlatesThe tarsal plates consist of dense, fibrous tissue 1–1.5 mm thick that imparts structural integrity to the eyelids. Each plate measures about 25 mm horizontally and is curved gently to conform to the contour of the anterior globe; the central height of the tarsal plates is 8–12 mm in the upper eyelid and 3.5–4 mm in the lower. Medially and laterally they taper to 2 mm in height as they pass into the canthal tendons. Within each tarsus are the meibomian glands, numbering about 25 in the upper lid and 20 in the lower lid. These are holocrine-secreting seba-ceous glands that are not associated with lash follicles. They produce the lipid layer of the precorneal tear film.

Canthal TendonsMedially, the tarsal plates pass into fibrous bands that form the crura of the medial canthal tendon. These lie between the orbicularis muscle anteriorly and the conjunctiva posteriorly. The superior and inferior crura fuse to form a stout common tendon that inserts via three limbs (see Fig. 12-1-3).4 The anterior limb inserts onto the orbital process of the maxillary bone in front of and above the anterior lacrimal crest. It provides the major support for the medial canthal angle. The posterior limb arises from the common tendon near the junction of the superior and inferior crura and passes between the canaliculi. It inserts onto the posterior lacrimal crest just in front of Horner’s muscle and directs the vector forces backward to maintain close approximation with the globe. The superior limb of the medial canthal tendon arises as a broad arc of fibers from both the anterior and posterior limbs. It passes upward to insert onto the orbital process of the frontal bone. The posterior head of the preseptal orbicularis muscle inserts onto this limb, and the unit forms the soft tissue roof of the lacrimal sac fossa. This extension pro-vides vertical support to the canthal angle,19 and appears to play a role in the lacrimal pump mechanism.

Laterally, the tarsal plates pass into not very well developed fibrous strands that become the crura of the lateral canthal tendon. This is a distinct entity separate from the orbicularis muscle; it measures about 1 mm in thickness, 3 mm in width, and approximately 5–7 mm in length.20 The insertion of these fibrous strands extends posteriorly along the lateral orbital wall, where it blends with strands of the lateral check ligament from the sheath of the lateral rectus muscle.

ConjunctivaThe conjunctiva is a mucous membrane that covers the posterior sur-face of the eyelids and the anterior pericorneal surface of the globe. The palpebral portion is applied closely to the posterior surface of the tarsal plate and the sympathetic tarsal muscle of Müller. It is continuous around the fornices above and below, where it joins the bulbar conjunc-tiva. Small accessory lacrimal glands are located within the submucosal connective tissue.

A small mound of tissue, the caruncle, is at the medial canthal angle. The caruncle consists of modified skin that contains fine hairs, sebaceous glands, and sweat glands. Just lateral to the caruncle is a vertical fold of conjunctiva, the plica semilunaris.

NERVES TO THE EYELIDSThe motor nerves to the orbicularis oculi muscle derive from the facial nerve (seventh cranial nerve) through its temporal and zygomatic branches (Fig. 12-1-4). These branches innervate the frontalis and orbicularis muscles, respectively. The buccal, mandibular, and cervical branches innervate muscles of the lower face and neck.21

The sensory nerves to the eyelids derive from the ophthalmic and maxillary divisions of the trigeminal nerve (Fig. 12-1-5). Sensory input from the upper lid passes to the ophthalmic division primarily through

Fig. 12-1-3 Levator aponeurosis and medial and lateral canthal tendons. (Adapted with permission from Dutton JJ. Atlas of clinical and surgical orbital anatomy. London: Elsevier Saunders; 2011. p. 149.

LEVATOR APONEUROSIS

levatorpalpebraesuperiorismuscle

levatoraponeurosis

fascial slips toorbicularis muscle

medialhorn

lateral horn

lateral canthaltendon

medialcanthal tendon

capsulopalpebralfascia

Whitnall'sligament

tarsal plate, but it may be as much as 10–15 mm above it.7 In the lower eyelid the septum fuses with the capsulopalpebral fascia several mil-limeters below the tarsus, and the common fascial sheet inserts onto the inferior tarsal edge.8,9

Preaponeurotic Fat PocketsThe preaponeurotic fat pockets in the upper eyelid and the precapsu-lopalpebral fat pockets in the lower eyelid are anterior extensions of extraconal orbital fat. These are surgically important landmarks and help identify a plane immediately behind the orbital septum and ante-rior to the major eyelid retractors. In the upper eyelid, two fat pockets typically occur: a medial pocket and a central one.10 In the lower eyelid, three pockets occur: medial, central, and lateral.11

Major Eyelid RetractorsThe retractors of the upper eyelid consist of the levator palpebrae and Müller’s muscles.12,13 The levator palpebrae superioris arises from the lesser sphenoid wing and runs forward just above the superior rectus muscle. Near the superior orbital rim, a condensation along the muscle sheath attaches medially and laterally to the orbital walls. This is the superior transverse orbital ligament of Whitnall. It provides some sup-port for the fascial system that maintains spatial relationships between a variety of anatomical structures in the superior orbit.

From Whitnall’s ligament the muscle passes into its aponeurosis (Fig. 12-1-3). This sheet continues downward 14–20 mm to its inser-tion near the marginal tarsal border. The aponeurotic fibers are most firmly attached at about 3–4 mm above the eyelid margin.14,15 The aponeurosis also sends numerous delicate interconnecting slips for-ward and downward to insert onto the interfascicular septa of the pre-tarsal orbicularis muscle and subcutaneous tissue. These slips main-tain the close approximation of the skin, muscle, aponeurosis, and tarsal lamellae, and integrate the distal eyelid as a single functional unit. This relationship defines the upper eyelid crease in both whites and blacks.

As the levator aponeurosis passes into the eyelid from Whitnall’s ligament, it broadens to form the medial and lateral ‘horns.’ The lateral horn forms a prominent fibrous sheet that indents the posterior aspect of the lacrimal gland, and so defines its orbital and palpebral lobes. The medial horn is not as well developed. Together, the two horns serve to distribute the forces of the levator muscle along the aponeurosis and the tarsal plate.

In the lower eyelid, the capsulopalpebral fascia is a fibrous sheet that arises from Lockwood’s ligament and the sheaths around the inferior rectus and inferior oblique muscles. It passes upward and generally fuses with fibers of the orbital septum about 4–5 mm below the tarsal

Clinical Anatomy of the Eyelids

12.1

1257Access the complete reference list online at

Fig. 12-1-4 Motor nerve supply to the eyelids: the facial nerve. (Adapted with permission from Dutton JJ. Atlas of clinical and surgical orbital anatomy. London: Elsevier Saunders; 2011. p. 155.)

MOTOR NERVES

temporal branchzygomaticbranch

facial nerve,main trunk

buccal branch

mandibularbranch

cervical branch

Fig. 12-1-5 Sensory nerve supply from the eyelids. (Adapted with permission from Dutton JJ. Atlas of clinical and surgical orbital anatomy. London: Elsevier Saunders; 2011. p. 155.)

SENSORY NERVES

supratrochlearnerve

infratrochlearnerve

infraorbitalnerve

supraorbitalnerve

zygomatico-temporal nerve

zygomatico-facial nerve

lacrimal nerveFig. 12-1-6 Arterial supply to and venous drainage from the eyelids. (Adapted with permission from Dutton JJ. Atlas of clinical and surgical orbital anatomy. London: Elsevier Saunders; 2011. p. 156.)

superior palpebralartery

inferiormarginalarterial arcade

superiormarginalarterial arcade

superiorperipheralarterial arcade

lateralpalpebral artery

supraorbital artery

supratrochlear artery

medial palpebral

artery

angularartery

facial artery

lateral palpebralvein

anteriorfacial vein

inferiorperipheralvenous arcade

superiorperipheralvenousarcade

superior palpebralvein

supraorbital vein

nasofrontalvein

medialpalpebral

veins

angular vein

ARTERIAL SUPPLY AND VENOUS DRAINAGE

Arterial supply

Venous drainage

its main terminal branches, the supraorbital, supratrochlear, and lac-rimal nerves. The infratrochlear nerve receives sensory information from the extreme medial portion of both upper and lower eyelids. The lower eyelid sends sensory impulses to the infraorbital nerve. The zygo-maticofacial branch from the maxillary nerve innervates the lateral portion of the lower lid, and part of the infratrochlear branch receives input from the medial lower lid.

VASCULAR SUPPLY TO THE EYELIDSVascular supply to the eyelids is extensive. The posterior eyelid lamel-lae receive blood through the vascular arcades. In the upper eyelid, a marginal arcade runs about 2 mm from the eyelid margin, and a

peripheral arcade extends along the upper border of the tarsus between the levator aponeurosis and Müller’s muscle (Fig. 12-1-6). These arcades are supplied medially by the superior medial palpebral vessels from the terminal ophthalmic artery, and laterally by the superior lat-eral palpebral vessel from the lacrimal artery. The lower lid arcade receives blood from the medial and lateral inferior palpebral vessels.

The venous drainage system is not as well defined as the arterial system. Drainage is mainly into several large vessels of the facial sys-tem (see Fig. 12-1-6). Lymphatic drainage from the eyelids is restricted to the region anterior to the orbital septum. Drainage from the lateral two-thirds of the upper eyelid and the lateral one-third of the lower eyelid proceeds inferiorly and laterally into the deep and superficial parotid and submandibular nodes. Drainage from the medial one-third of the upper eyelid and the medial two-thirds of the lower eyelid occurs medially and inferiorly into the anterior cervical nodes.

KEY REFERENCESDutton JJ. Atlas of clinical and surgical orbital anatomy. 2nd ed. London: Elsevier Saunders; 2011.Kakizaki H, Malhotra R, Madge SN, et al. Lower eyelid anatomy: an update. Ann Plast Surg

2009;63:344–51.Kakizaki H, Malhotra R, Selva D. Upper eyelid anatomy: an update. Ann Plast Surg 2009;63:336–43.Lim HW, Paik DJ, Lee YJ. A cadaveric anatomical study of the levator aponeurosis and Whitnall’s

ligament. Korean J Ophthalmol 2009;23:183–7.Persichetti P, Di Lella F, Delfino S, et al. Adipose compartments of the upper eyelid: anatomy

applied to blepharoplasty. Plast Reconstr Surg 2004;113:373–8.Ridgway JM, Larrabee WE. Anatomy for blepharoplasty and brow-lift. Facial Plast Surg

2010;26:177–85.

Clinical Anatomy of the Eyelids

12.1

1257.e1

REFERENCES1. Most SP, Mobley SR, Larabee Jr WF. Anatomy of the eyelids. Facial Plast Surg Clin North Am

2005;13:487–92.2. Goldberg RA, McCann JD, Fiaschetti D, et al. What causes eyelid bags? Analysis of 114

consecutive patients. Plast Reconstr Surg 2005;115:1395–402.3. Ridgway JM, Larrabee WE. Anatomy for blepharoplasty and brow-lift. Facial Plast Surg

2010;26:177–85.4. Becker BB. Tricompartment model of the lacrimal pump mechanism. Ophthalmology

1992;99:1139–45.5. Kakizaki H, Zako M, Miyaishi O, et al. The lacrimal canaliculi and sac bordered by the Horner’s

muscle form a functional lacrimal drainage system. Ophthalmology 2005;112:710–16.6. Kakizaki H, Selva D, Asamoto K, et al. Orbital septum attachment sites on the levator

aponeurosis in Asians and whites. Ophthal Plast Reconstr Surg 2010;26:265–8.7. Lim HW, Paik DJ, Lee YJ. A cadaveric anatomical study of the levator aponeurosis and

Whitnall’s ligament. Korean J Ophthalmol 2009;23:183–7.8. Kakizaki H, Jinsong Z, Zako M, et al. Microscopic anatomy of Asian lower eyelids.

Ophthal Plast Reconstr Surg 2006;22:430–3.9. Meyer DR, Linberg JV, Wobig JL, et al. Anatomy of the orbital septum and associated eyelid

connective tissue. Ophthal Plast Reconstr Surg 1991;7:104–13.10. Persichetti P, Di Lella F, Delfino S, et al. Adipose compartments of the upper eyelid: anatomy

applied to blepharoplasty. Plast Reconstr Surg 2004;113:373–8.

11. Oh CS, Chung IH, Kim YS, et al. Anatomic variations of the infraorbital fat compartments. J Plast Reconstr Aesthet Surg 2006;59:376–9.

12. Kakizaki H, Malhotra R, Selva D. Upper eyelid anatomy: an update. Ann Plast Surg 2009;63:336–43.

13. Kakizaki H, Malhotra R, Madge SN, et al. Lower eyelid anatomy: an update. Ann Plast Surg 2009;63:344–51.

14. Anderson RL, Beard C. The levator aponeurosis. Attachments and their clinical significance. Arch Ophthalmol 1977;95:1437–41.

15. Collin JRO, Beard C, Wood I. Experimental and clinical data on the insertion of the levator palpebrae superioris muscle. Am J Ophthalmol 1987;85:792–801.

16. Manson PN, Lazarus RB, Magar R, et al. Pathways of sympathetic innervation to the superior and inferior (Müller’s) tarsal muscles. Plast Reconstr Surg 1986;78:33–40.

17. Kuwabara T, Cogan DG, Johnson CC. Structure of the muscles of the upper eyelid. Arch Ophthalmol 1975;93:1189–97.

18. Hawes MJ, Dortzbach RK. The microscopic anatomy of the lower eyelid retractors. Arch Ophthalmol 1982;100:1313–18.

19. Poh F, Kakizaki H, Selva D, et al. The anatomy of the medial canthal tendon in Caucasians. Clin Experiment Ophthalmol 2012;40:170–3.

20. Gioia VM, Linberg JV, McCormick SA. The anatomy of the lateral canthal tendon. Arch Ophthalmol 1987;105:529–32.

21. Saylam C, Ucerler H, Orham M, et al. Anatomic guides to precisely localize the zygomatic branches of the facial nerve. J Craniofac Surg 2006;17:50–3.