Continuing Education Activity

Entropion is an inversion of the eyelid margin and is an extremely common lid malposition. Often the eyelashes are directed posteriorly at the globe. When the eyelashes are directed toward the globe, corneal and conjunctival damage can ensue, potentially leading to corneal disease. Surgical repair of entropion is performed to restore the eyelid to its proper anatomical alignment. This, in turn, protects the eye from injury and reduces associated symptoms. This activity describes the four types of entropion: congenital, involutional, acute spastic, and cicatricial. This activity also reviews the evaluation and treatment of entropion and discusses the role of the interprofessional team in evaluating and treating patients with this condition.

Objectives:

• Differentiate the 4 types of entropion by etiology and underlying risk factors.
• Identify appropriate indications for entropion repair and manage postoperative complications.
• Compare the various approaches for surgical correction of entropion and the risks and benefits of each.
• Implement efficient and effective interprofessional practices for the management of entropion in the prehospital, hospital, and postoperative settings.

Introduction

Entropion is an inversion of the eyelid margin, wherein the margin is abnormally rotated towards the globe. This malposition is extremely common and disrupts the normal tear film and protective functions of the eyelid. This malposition often directs the eyelashes posteriorly at the globe, which can cause corneal and conjunctival damage, potentially leading to chronic corneal disease. Entropion can be unilateral or bilateral, involving either the upper or lower eyelids. There are four types of entropion: congenital, involutional, acute spastic, and cicatricial. The most common cause of entropion of the lower eyelid is involutional, while in the upper eyelid it is cicatricial.[1][2][3]

The risk of developing entropion increases with increasing age. This is particularly true for involutional entropion, which occurs secondary to age-related weakening and laxity of the muscles and tendons.[4] As we age, the canthal tendons relax, and the eyelid retractors attenuate, causing malposition of the eyelid margin. 

Infection, irritation, and inflammation are the primary causes of acute spastic entropion. This condition occurs most commonly after intraocular surgery in patients with unrecognized preoperative involutional eyelid changes. Continual orbicularis oculi muscle contraction causes inward rotation of the eyelid margin. This, in turn, causes corneal irritation due to lash rub, which perpetuates the problem.

Cicatricial entropion is caused by a tarsoconjunctival contracture. Any mechanism that results in increased scar tissue formation, especially in the inner and middle layers of the eyelid, can put an individual at risk for developing cicatricial entropion. Some common risk factors include prior burns, infection, inflammation, connective tissue disease, and trauma, including transconjunctival surgery.[5][6]

Anatomy and Physiology

The eyelid is composed of multiple layers. From superficial to deep, these layers are skin, muscles of protraction and the orbicularis oculi, orbital septum, orbital fat, muscles of retraction, tarsus/tarsal plate, and conjunctivae.[7] The skin of the eyelid is much thinner relative to other skin throughout the body. Derangements in any of these layers can theoretically lead to eyelid malposition, including entropion.

Multiple nerves supply the eyelid. The nerves supplying the superior lid are the infratrochlear, supratrochlear, supraorbital, and lacrimal nerves of the ophthalmic division of the trigeminal nerve (cranial nerve V division V1). The nerves that supply the lower eyelid are the infratrochlear and infraorbital nerves of the maxillary division of the trigeminal nerve (cranial nerve V division V2).

Anastomoses of the lateral and medial palpebral arteries give rise to the blood supply of the upper and lower eyelids. These arteries originate from the lacrimal artery and the ophthalmic artery, respectively.

The tarsus, orbicularis oculi, lid retractors, and canthal tendons support the lower eyelid. The canthal ligaments and tarsal plate horizontally stabilize the lid; any weakening of these structures permits the inversion of the lid. The lid retractors support the eyelid vertically. The levator aponeurosis and the Mueller muscle support the upper eyelid. The lower lid retractors connect to the orbicularis oculi muscle and skin overlying the muscle.[8] As these extensions weaken, the preseptal orbicularis can migrate superiorly and supersede the pretarsal musculature, causing the eyelid margin to rotate inward against the eye. Orbital fat content and overall volume decrease with age or after injury, potentially resulting in enophthalmos. The resultant relative increase in space between the eye and the eyelid creates a lid laxity or the ability for the orbicularis to override the tarsus, causing entropion to develop.

Indications

Symptoms of entropion can include foreign body sensation in the eye, eye pain, excessive tearing or epiphora, and blurred vision; patients with symptomatic entropion on clinical examination are candidates for entropion repair. Early entropion repair before developing clinical signs of corneal exposure or trauma will potentially prevent more serious sequelae, including irreversible vision loss. Those with reversible corneal changes, such as corneal abrasion, should undergo repair more urgently; reversible changes may progress to irreversible changes if left untreated.

Patients with early, reversible corneal damage should also be treated with temporizing measures while awaiting surgery to prevent further damage. These patients may benefit from increased ocular lubrication with ointments or artificial tears, botulinum toxin injection, tarsorrhaphy, or Quickert suturing.[9][10][11]

Contraindications

Contraindications to entropion repair include patients who are unable to tolerate the procedure. In addition, medical management of any underlying etiology, such as autoimmune or connective tissue disease, must be optimized before a surgical repair is considered. Uncontrolled inflammation or infection worsens the prognosis, increases the risk of complications, and promotes the progression of the condition.

Patients with irreversible vision loss in the affected eye may not require repair as urgently as those with some degree of vision. However, entropion repair may still be indicated for pain relief or other symptom control.

Equipment

The following equipment is needed: No. 15 Bard-Parker blade, Castroviejo needle driver, Westcott-Aldrich scissors, Castroviejo 0.5 forceps, monopolar or bipolar cautery, 4-0 silk suture, 5-0 and 6-0 polyglactin (Vicryl) suture, corneal shield, and antibiotic ophthalmic ointment.

Personnel

Ophthalmologists, oculoplastic surgeons, facial plastic surgeons, and plastic surgeons are all potentially qualified to perform these repairs. The surgeon's overall experience with entropion repair is an important predictor of surgical success.[12]

Preparation

The patient should be appropriately examined before surgical intervention and deemed appropriate for surgery by an ophthalmologist or a surgeon trained in entropion evaluation and repair. The patient should be educated about the associated risks and benefits of the intervention, including alternative therapies available. All possible complications should be discussed. Lastly, all questions from the patient should be answered.

The operation can be performed under general anesthesia or with topical and local anesthesia with or without additional intravenous sedation or oral sedatives. The anesthetic modality is dictated by surgeon experience and patient preference.

Technique or Treatment

Internal Approach with Tarsal Strip for Involutional Entropion Repair

The patient is prepped and draped in the usual sterile, full-face preparation. A corneal shield is placed in the affected eye.

A No. 15 Bard-Parker blade is used to make a 3-mm to 4-mm incision in the lateral canthal angle. The lateral canthal tendon and inferior crus are then disinserted. A tarsal strip is then created using Westcott scissors and 0.5 forceps. Hemostasis is maintained with cautery. A 4-0 silk traction suture is placed through the lash line or grey line of the lower lid. The lid is then everted. An incision in the conjunctiva below the inferior tarsal border from the lateral canthus immediately lateral to the punctum is made. Dissection is continued toward the inferior orbital rim with the 0.5-mm forceps and Westcott scissors. The orbital fat is dissected to expose the lower lid retractors while maintaining meticulous hemostasis.

The retractors are then dissected free from the conjunctiva. A 6-0 Vicryl suture is passed through the inferior, anterior portion of the tarsus. It is then passed through the lower lid retractors beneath the conjunctiva toward the globe, advancing them onto the anterior, inferior tarsus. Sutures are then placed across the lower lid. The sutures induce appropriate eversion of the eyelid without displacing the puncta. Additionally, a 5-0 Vicryl suture is passed in a whipstitch fashion through the anterior and posterior tarsus of the lid. The suture is then passed through the periosteum at the lateral orbital rim. The suture is temporally tightened to assess the lid position.

Once the appropriate lid position is achieved, a buried, interrupted 6-0 Vicryl suture is passed from gray line to gray line, upper to lower lid, to reform the lateral canthal angle. The 5-0 Vicryl suture is tied down. The orbicularis is closed with a 6-0 Vicryl in a buried, interrupted method. The skin incision is closed using simple, interrupted 6-0 plain gut sutures. Antibiotic ophthalmic ointment should be applied to the eye and all suture sites.

External Approach for Involutional Entropion Repair

The patient is prepped and draped in the usual sterile, full-face preparation. A corneal shield is placed in the affected eye.

Attention is turned to the affected lower lid. A 4-0 silk traction suture is placed through the lash line or grey line of the affected lid. A surgical marking pen is used to mark an incision at the inferior border of the tarsus from the puncta to the lateral canthus. A No. 15 Bard-Parker blade is used to make a skin incision at the marking. The assistant then elevates the inferior portion of the incision with a lacrimal rake while caudally tractioning the cheek tissue. Dissection is continued toward the inferior orbital rim using 0.5 forceps and Westcott scissors.

The orbital septum is opened, and the preaponeurotic fat is identified. The fat is dissected to expose the lower lid retractors. Hemostasis is maintained with cautery. The retractors are dissected free from the conjunctiva for 5 mm to 10 mm. A 6-0 Vicryl suture is passed through the inferior, anterior portion of the tarsus. It is then passed in a buried fashion through the lower lid retractors advancing them onto the inferior tarsus. Three or four such sutures are placed at an equidistance across the affected lower eyelid. This should cause appropriate eversion of the eyelid without displacing the puncta from the proper position. The skin incision is closed using simple, interrupted 6-0 plain gut sutures. The corneal shield is then removed from the affected eye. Finally, the antibiotic ophthalmic ointment is instilled into the eye and on all suture sites.

Complications

Complications of entropion repair include hemorrhage, undercorrection or overcorrection, lower lid retraction, infection, wound dehiscence, scarring, corneal injury, milphosis, and eyelid margin necrosis.[13][14][15]

Clinical Significance

Surgical repair of entropion is performed to restore the eyelid to its proper anatomical alignment. This, in turn, protects the eye from injury and reduces associated symptoms.

Perioperative medical management is vital to prevent further corneal damage. This can include ocular lubrication with ointments, artificial tears, or ocular protection with contact lenses. Botulinum toxin or Quickert sutures can temporarily provide relief, but surgical correction is the only definitive treatment.

Enhancing Healthcare Team Outcomes

Patients with entropion may first present to the advanced practice or primary care provider. Since entropion is a progressive disorder with the potential to cause injury to the cornea, it is important to refer these patients to an oculoplastic surgeon or an ophthalmologist. Several techniques exist for repairing entropion, and skill and experience are required. 

Operating room and ophthalmology nurses assist in care and provide patient education. The outcomes for most patients are good, but some patients require revision, and cosmesis is not always perfect.[16][17]

Nursing, Allied Health, and Interprofessional Team Interventions

Preoperative visual acuity should be noted in both the affected and unaffected eye as a baseline. Any acute change in visual acuity preoperatively should prompt further evaluation, as this would not be expected from simple lid malposition, and may reflect corneal or other ocular pathology. Formal optometric examination may also be of benefit, particularly if the patient has known additional ocular pathology, such as glaucoma.

Nursing, Allied Health, and Interprofessional Team Monitoring

Postoperative nursing education includes application of ophthalmic ointment twice daily to the eye until seen again in clinic. The patient should be instructed to keep the eye clean and dry and to use artificial tears daily. Patients should avoid manipulating the eyelids and should refrain from wearing contact lenses until cleared to do so by their surgeon.