Direct Closure and Lateral Cantholysis

Aaron Fay

John Nguyen

DEFINITION

The primary objectives of eyelid reconstruction are to
- Restore anatomic alignment and dynamic function of the eyelids
- Create a stable eyelid margin with acceptable vertical lid height of both anterior and posterior lamellae
- Maintain adequate eyelid closure
- Optimize appearance and symmetry
Full-thickness eyelid defects involving up to one-third of the margin can be repaired by direct closure, depending very much on the age of the patient, though sometimes the addition of a lateral cantholysis is required to allow adequate mobilization of the lateral lid.

ANATOMY

The eyelids are conceptually considered as the anterior and posterior lamella (FIG 1). The anterior lamella consists of skin and orbicularis oculi muscle. The posterior lamella contains tarsus and palpebral conjunctiva.
- The gray line is an important landmark that separates these two lamellas. This line is important for eyelid margin repair and represents the superficial portion of the orbicularis oculi muscle known as the muscle of Riolan. From the eyelid margin to the superior (upper lid) or inferior (lower lid) edge of tarsus, the upper eyelid tarsal plate is approximately 10 mm tall centrally and tapers toward the medial and lateral canthal tendons, whereas the lower eyelid tarsal plate measures approximately 4 mm high and tapers slightly.
Above the upper eyelid crease, eyelid anatomy is substantially different, where the concept of lamellae begins to break down. The posterior lamella in this anatomic region includes the conjunctiva, Mueller muscle, and the aponeurosis of levator palpebrae superioris. Most authors now consider a “middle lamella” that includes the preaponeurotic fat and orbital septum. This leaves the orbicularis oculi and skin to constitute the anterior lamella.
The lateral eyelid also incorporates the palpebral lobe of the lacrimal gland. The lower lid contains analogous structures but notably contains a third fat pad laterally (whereas the lacrimal gland occupies that space in the upper lid). The canthal tendons suspend the eyelids medially and laterally and the lacrimal drainage system including the punctum, canaliculus, common canaliculus, and the medially located lacrimal sac.
Vascular supply to the eyelids is provided by the marginal arcade, near the eyelid margins, and the peripheral arcades, coursing along the superior tarsal edge in the upper lid and along the inferior tarsal edge in the lower lid.
Palpebral width, on average, measures 30 mm in adults. The lower lid typically rests at the inferior corneal limbus, with the lateral canthus 2 mm higher than the medial canthus. The upper lid rests slightly inferior to the superior corneal limbus with the peak of the upper lid between the medial corneal limbus and the medial border of the pupil.
The skin of the eyelid is unique in that it is the thinnest skin found anywhere on the body and is devoid of subcutaneous fat, hence an intimate connection with orbicularis oculi, another thin layer covering the orbital septum from lid margin to brow.

PATHOGENESIS

Eyelid margin defects can be partial thickness or full thickness, may occur at different positions on the eyelid, and most commonly result from trauma in young men.
Lacrimal injury may concurrently exist, especially when the laceration is in the medial canthal region. This is more common in children.
Mechanisms include tissue stretch, crush, avulsion, or tear. Tissue loss is rare, so direct closure without the need for cantholysis is typically performed.
Resection of malignant eyelid tumors (most often basal cell carcinoma, squamous cell carcinoma, and sebaceous cell carcinoma) results in defects of various sizes. Because surgical margins are needed, these surgeries often cause large defects that may require cantholysis when closing primarily.
Closure of larger eyelid defects requires local flaps such as Tenzel semicircular flap which is discussed in subsequent chapters.

NATURAL HISTORY

Incomplete closure of eyelid defects can lead to eyelid notching, exposure, entropion, ectropion, trichiasis, corneal injury, eyeball rupture, and corneal blindness.

PATIENT HISTORY AND PHYSICAL FINDINGS

Assessment of the eyelid defect typically occurs after stabilization of life-threatening conditions in patients with traumatic injuries.
History should include nature of the injury; type of trauma; the extent of trauma; prior ocular and periocular surgical history; visual changes; tetanus vaccination status of the
patient and the assaulting animal in case of bites; recent food or liquid ingestion; and drug allergy. Bite, hook, or clawing trauma may be suggestive of canalicular laceration.
A detailed assessment of the defect must include the width, height, and eyelid layers involved.
- A defect in the medial canthal region requires an additional examination for canalicular and medial canthal tendon integrity; complete eyelid eversion is indicative of loss of canthal tendon attachment.
- In many cases, the medial canthal tendon can be assessed quickly by distracting the upper and lower lid margins laterally and observing the degree of migration of the medial commissure.
- When a laceration appears to involve the medial eyelid, the punctum should be dilated and the canaliculus probed. Superficial-appearing lacerations in this region are notoriously misleading.
- The eyelid is also inspected for scarring or previous incision sites. Prior irradiation, burn injury, or skin conditions such as scleroderma and ichthyosis may limit the amount of skin stretching needed for primary wound closure.
- Laxity of the lid, especially in elderly patients, is also examined as it may facilitate closure and precluding the need for cantholysis.
- In cases of trauma, careful examination for debris or retained foreign bodies or eyeball laceration (“ruptured globe”) is important. Globe injuries typically dictate the timing of lid repair.

FIG 1 • A. Anatomy of the eyelid demonstrating the components of the anterior and posterior lamellas. B. Position of the gray line separating the anterior and posterior lamella.

NONOPERATIVE MANAGEMENT

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