Entropion is an inversion of the eyelid margin. Often the eyelashes are directed posteriorly at the globe. It is an extremely common lid malposition. When the lashes are directed toward the globe, it can cause corneal and conjunctival damage. Ultimately, this can lead to corneal disease. An entropion can be unilateral or bilateral. There are four types of entropion: congenital, involutional, acute spastic, and cicatricial. The most common type in the lower eyelids is involutional, while in the upper eyelid it is cicatricial.
The older an individual is, the greater the chances of having an entropion. This is secondary to the weakening of the muscles and tendons, the most common type of entropion. Any mechanism that results in increased scar tissue formation can put an individual at risk for forming an entropion. Some common risk factors are the following: prior burns, trauma, infection, or inflammation. Entropion is thought to occur more often in females because females tend to have smaller tarsal plates than males.
Entropion can be caused by horizontal eyelid laxity, attenuation or disinsertion of eyelid retractors, overriding by the preseptal orbicularis oculi muscle, previous surgeries, infection, inflammation, or congenital origins. Involutional changes are the most common etiology of entropion. As we age, the canthal tendons relax, and the eyelid retractors attenuate, causing misposition 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 who had unrecognized involutional eyelid changes preoperatively. Continual orbicularis oculi muscle contraction causes inward rotation of the eyelid margin. This, in turn, causes ocular, specifically corneal irritation, due to lash rub which perpetuates the problem. A tarsoconjunctival contracture causes Cicatricial entropion. Any mechanism that results in increased scar tissue formation can put an individual at risk for forming a cicatricial entropion. Some common risk factors are the following: prior burns, trauma, infection, or inflammation.
The eyelid is composed of multiple layers. Superficial layers to deep layers include the following: skin, muscles of protraction/orbicularis, orbital septum, orbital fat, retraction muscles, tarsus, and conjunctiva. The skin in relation to other skin is much thinner along the eyelid. Multiple nerves supply the eyelid. The superior lid's nerves are the infratrochlear, supratrochlear, supraorbital and lacrimal nerves of V1. The nerves of the lower eyelid are the infratrochlear and infraorbital nerve of V2. The blood supply to both of the lids is created by an anastomosis of the lateral and medial palpebral arteries. These arteries branch off the lacrimal artery and ophthalmic artery.
In general, the lower lid is supported by the tarsus, orbicularis, lid retractors, and canthal tendons. The canthal ligaments and tarsal plate horizontally stabilize the lid. The weakening of these structures permits the inversion of the lid. The lid retractors support the eyelid vertically. In the upper lid, the levator aponeurosis and Mueller's muscle provide this role. The lower lid retractors connect to the orbicularis muscle and skin overlying the muscle. As these extensions weaken, the preseptal orbicularis can move superiorly and supersede the pretarsal muscle causing the eyelid margin to rotate against the eye. Orbital fat content and overall volume decrease with age or after injury, often resulting in enophthalmos. The greater space between the eye and the eyelid creates a lid laxity or the ability for the greater orbicularis override driving an entropion to develop.
Patients with symptomatic entropion on a clinical exam.
A patient who is unable to tolerate the procedure or have not attempted medical management. Medical management of the underlying etiology needs to be controlled first, and then surgical correction can be considered. If inflammation or infection are not controlled, the prognosis is worse, higher risk of complications, and can often progress.
The following equipment is needed: No. 15 bard-parker blade, Castroviejo needle driver, Westcott scissors, Castroviejo 0.5 forceps, and cautery (monopolar or bipolar), 4-0 silk suture, 6-0 vicryl suture, 5-0 vicryl suture, corneal shield, and antibiotics ointment.
Ophthalmologist or surgeon trained in oculofacial plastic surgery.
The patient should have been properly examined before surgical intervention and deemed appropriate for surgery by an ophthalmologist or surgeon trained in oculoplastic procedures. The patient needs to 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.
Internal Approach with Tarsal Strip for Involutional Entropion Repair
The patient is prepped and draped in the usual sterile, full-face oculofacial plastic surgery fashion. A corneal shield is placed in the (right/left) eye. A No. 15 Bard-Parker blade was 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 lateral to the puncta is made. Dissection is continued toward the inferior orbital rim with a 0.5 forceps and Westcott scissors. The orbital fat is dissected to expose the lower lid retractors while maintaining 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 lid position. Once appropriate. 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 was closed using simple, interrupted 6-0 plain gut sutures. Antibiotics 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 oculofacial plastic surgery fashion. A corneal shield is placed in the (right/left) eye. Attention is turned to the (right/left) lower lid. A 4-0 silk traction suture is placed through the (lash line/grey line) of the (right/left) lower lid. A surgical marking pen is used to mark an incision at the inferior border of the tarsus from approximately from the puncta to the lateral canthus. A #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 identified. The fat is dissected to expose the lower lid retractors. Hemostasis is maintained with (monopolar/bipolar) cautery. The retractors are then dissected free from the conjunctiva for 5-10mm. A 6-0 Vicryl suture (on a spatulated needle) 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 to four such sutures are placed an equidistance across the (right/left) lower eyelid. This should cause appropriate eversion of the eyelid without displacing the puncta from the proper position.The skin incision is then closed using simple, interrupted 6-0 plain gut sutures. The corneal shield is then removed from the (right/left) eye. The antibiotic ophthalmic ointment is instilled into the (right/left) eye and on all suture sites.
Complications include the following: hemorrhage, overcorrection, lower lid retraction, under correction, infection, wound dehiscence, scarring, corneal injury, milphosis, and eyelid margin necrosis.
The clinical significance is to restore the eyelid to it proper anatomical alignment. This, in turn, protects the eye from injury and reduces associated symptoms. Management can include ocular lubrication with ointments, artificial tears, or ocular protection with contact lenses. Botulinum toxins or Quickert sutures can temporarily provide relief, but only surgical treatment provides definitive treatment.