Malposition of the Eyelids

Congenital Entropion

Congenital entropion, although rare, can affect both lower and upper eyelids. Proposed mechanisms of congenital upper eyelid entropion have included direct mechanical pressure in utero or intrauterine dysgenesis of the tarsus (kinked tarsus). On eversion, the posterior tarsus in tarsal kink syndrome demonstrates a large horizontal kinking (scarring) of the tarsus that results in inversion of the lid margin and lashes. Proposed pathophysiology of congenital lower eyelid entropion includes vertical deficiency in the posterior eyelid lamella with or without disinsertion of the lower eyelid retractor muscles, horizontal laxity of the medial and lateral canthal tendons, and facial nerve palsies. Ocular anomalies may also be present. Sires reported a retrospective clinical series of 25 cases of congenital horizontal tarsal kink. The classic presentation was male, Caucasian, diagnosed at 7 weeks of age, bilateral or right sided, and with corneal ulceration in 50% of patients.

Congenital entropion should not be confused with epiblepharon, commonly seen in patients of Asian descent, in which a hypertrophic fold of lower lid skin and orbicularis muscle overrides the lid margin and causes the lashes to rotate inward. Pulling the redundant skinfold down gently can often demonstrate that the underlying eyelid margin is in proper anatomic position. Some patients with epiblepharon, in contrast to congenital entropion, may outgrow the lid malposition as the midfacial bones and soft tissues mature.

Involutional Entropion

Involutional entropion is the most common form of entropion and typically involves the lower eyelids in elderly patients. Several factors in combination can contribute to involutional entropion. Horizontal laxity consists of medial canthal tendon laxity, lateral canthal tendon laxity, and tarsal degeneration. Normally, the medial canthal tendon prevents the inferior punctum from being pulled laterally more than 2–3 mm. Lateral displacement of more than 5 mm toward the limbus may warrant surgical correction of the medial canthal tendon ( Fig. 26.1 ). The “snap back” test is performed by pulling the eyelid down. When released, the eyelid should return sharply to its former apposition against the globe. Failure to do so indicates tarsal attenuation or lateral canthal tendon laxity. The eyelid distraction test is performed by measuring the distance with a ruler from the globe to the eyelid margin when the eyelid is pulled anteriorly from the globe. Distraction more than 6 mm from the cornea would be considered abnormal ( Fig. 26.2 ).

Disinsertion or attenuation of the retractor complex allows the inferior tarsus to move anteriorly and superiorly, causing the eyelid margin to turn inward. A white line corresponding to the leading edge of the disinserted retractor complex may be seen, separated from the inferior tarsus by a pink band that corresponds to the orbicularis visible through the conjunctiva ( Fig. 26.3 ). Because the capsulopalpebral fascial attachment to the inferior fornix remains intact, the inferior fornix may appear deepened when compared with the normal eye. The affected eyelid may also fail to retract inferiorly during downgaze in contrast to an intact lid that retracts in downgaze. It has been often suggested that resorption of orbital fat may further lead to age-related relative enophthalmos and worsened laxity from poor eyelid support.

In entropion, a factor that determines whether the unstable lower lid is going to turn inward is the preseptal fibers of the orbicularis muscle overriding the pretarsal fibers. When this occurs, inward pressure is applied to the lid margin. Asians may be more predisposed than Caucasians to involutional entropion due to a more anterior and superior protruding position of orbital fat within the eyelid.

Cicatricial Entropion

Contracture of the posterior lamella and subsequent entropion may occur secondary to surgical or trauma-related scarring, chemical burns, and inflammatory conditions such as trachoma, Stevens-Johnson syndrome, ocular cicatricial pemphigoid, acne rosacea, and chronic meibomitis. Any long-standing irritation can induce an added cicatricial component to any type of eyelid malposition. Upper eyelid entropion is typically cicatricial in etiology in contrast to the lower lid, in which involutional entropion is most common.

Acute Spastic Entropion

Any ocular irritation (e.g., blepharitis and allergies, following cataract or corneal surgery) can induce significant blepharospasm and subsequent entropion. The eyelids are squeezed tightly such that the orbicularis muscle causes inward rotation of the margin. This condition may resolve after several weeks and can affect any age group. In older patients, it may be a manifestation of a latent involutional entropion.

Differential Diagnosis

“Epiblepharon” is a congenital condition that occurs most commonly in Asian patients. The most common presentation is bilateral involvement of the lower eyelids. A thick horizontal fold of eyelid skin and orbicularis is seen overriding the margin, causing the lashes to be pushed backward toward the cornea ( Fig. 26.4 ). In contrast to congenital entropion, the tarsus and posterior margin remain in normal position. The contact of the lashes with the cornea can be present all the time or only in downward gaze. The problem is usually well tolerated because the lashes in children are fine and soft. As the facial bones grow, spontaneous resolution is common, although less often in Asians. Treatment is reserved for cases with significant irritation or a threat to corneal integrity. Similar to the anatomic abnormality in congenital entropion, the anterior insertions of the retractor complex that normally extend through pretarsal orbicularis to insert into the subcutaneous tissues to form the lid crease are absent. This failure to bind skin and orbicularis to the tarsus allows the formation of the horizontal roll seen clinically. Simple excision of the skinfold and strip of orbicularis muscle is frequently performed but does not directly correct the underlying anatomic defect. Quickert-Rathbun sutures may correct the defect by creating a scar between the skin, muscle, and retractor layers and creating a lid crease. Because many Asians do not normally have a lower lid crease, a rotating suture technique with a skin incision just below the lash line and buried sutures may avoid forming a scar and visible eyelid crease.

Medical Management

In spastic entropion, conservative management with lubrication, a bandage contact lens, or eyelid taping may break the cycle. Tape is applied near the eyelid margin to pull the margin away from the eye and horizontally and superiorly to simulate a lateral tarsal strip procedure ( Fig. 26.5 ). Tissue glues, such as cyanoacrylate glue, have been placed in the lower lid crease with a 20-gauge cannula to reposition the eyelids successfully. Seven of 10 patients had continued adhesions 1 week after application without ocular complications.

Blepharitis and meibomitis require lid hygiene and antibiotic ointment with or without steroid. Acne rosacea may respond to oral doxycycline. Small injections of botulinum toxin into the orbicularis muscle can be helpful in treating a spastic entropion, with an average duration effect of 12.5 weeks. Complications are few but include ecchymosis, epiphora, and diplopia. However, injection of botulinum can turn an involutional or spastic entropion into a flaccid ectropion if significant lower lid laxity is also present.

Surgical Management

The nonincisional suture technique described by Quickert and modified by Feldstein, as well as many others, may be a valuable temporizing measure. One needle of a double-armed 4-0 chromic catgut suture is passed deep into the fornix to secure the dehisced retractors, then passes adjacent to the inferior tarsus and exits higher through the skin at the level of midtarsus. The second needle is passed in the same way 3 mm adjacent to the first. The knot is then tied with enough tension to correct the entropion, without causing ectropion ( Fig. 26.6 ). Three to four sutures can be placed as needed across the eyelid to evert the margin. Resultant subcutaneous inflammatory cicatrix results indirectly in tightening of the retractors to the inferior tarsus and in fibrosis between orbicularis fibers and tarsus that may prevent vertical overriding. Sutures can be removed after 2–3 weeks if not yet resorbed. This procedure is considered temporary due to high recurrence rates, although one study showed that entropion recurred in 15% with only everting sutures after a mean follow-up of 31 months. Scheepers et al. found a high rate of recurrence up to 21% (6/29 patients) with the use of everting sutures alone.

Involutional Entropion

The literature describes numerous anterior and posterior techniques to correct involutional entropion. The anterior approach has a good success rate, although it requires more tissue dissection. ^, Ideally, either approach should address horizontal laxity, disinserted inferior retractors, and orbicularis muscle override.

Medial canthal tendon laxity is repaired first if present. Plication of the anterior crus of the medial canthal tendon can be addressed via a skin incision, a transconjunctival, or a transcaruncular approach. The medial canthal tendon should be tightened to the periosteum of the posterior lacrimal crest to minimize punctal ectropion, with care taken to avoid injury to the canaliculi and nasolacrimal sac.

Detached or attenuated lower lid retractors should always be reinserted. In the anterior approach, an infraciliary incision is created, and the skin is undermined to the junction of the pretarsal to the preseptal fibers. Dissection then passes through the muscle plane and orbital septum. The detached or attenuated inferior retractors, recognizable by their white color ( Fig. 26.7A ), are reattached to the inferior tarsal border (see Fig. 26.7B ) with absorbable or nonabsorbable sutures (e.g., 6-0 Vicryl).

It is important to correct any horizontal laxity with a lateral tarsal strip procedure in order to avoid postoperative recurrence. A lateral canthotomy is performed, and the inferior crus of the lateral canthal tendon lysed. The eyelid is pulled laterally to determine the amount of redundant lid. The eyelid is split into anterior and posterior lamellae, and the tarsal strip denuded of skin, eyelashes, and margin epithelium is anchored to the periosteum inside the lateral orbital rim at Whitnall tubercle using absorbable or nonabsorbable sutures (5-0 Vicryl or 5-0 prolene) ( Fig. 26.8 ). Orbicularis muscle myectomy, performed by excising a narrow horizontal strip of preseptal orbicularis muscle, creates a cicatricial barrier between pretarsal and preseptal orbicularis to prevent orbicularis override.

A posterior transconjunctival approach permits all the steps included in the anterior approach without a visible scar and is associated with a recurrence rate of 2%–9%. ^{, ,} The conjunctiva is incised below the tarsus, and the attenuated retractors are typically identified 5–10 mm below the inferior tarsal border. To reduce the overriding orbicularis muscle, a horizontal strip of muscle is excised with the cautery. The retractor complex is reinserted to the inferior tarsal border with absorbable suture, or the sutures may be passed full-thickness through the lid to be tied on the skin. Horizontal laxity is repaired similarly to the anterior approach.