Background
Lower lid ectropion is a very common condition in older persons. Frequency increases steadily with age. [1] Defined as an eversion of the eyelid away from the globe, the condition is classified according to its anatomic features as involutional, cicatricial, tarsal, congenital, or neurogenic/paralytic. Surgical approaches are directed toward the underlying etiologic factors. [2]
See the image below.
Problem
Ectropion is an outward turning of the eyelid margin. It occurs most often in the lower eyelid. The condition may be mild or severe and may involve all or part of the eyelid margin.
Epidemiology
Frequency
Ectropion is a very common condition in older persons. It is more frequently found in men than in women, which may be related to men generally having larger tarsal plates than women.
Etiology
Ectropion is most commonly observed as an involutional change associated with horizontal laxity of the involved eyelid. Ectropion may be classified into the following 5 types, ordered in decreasing frequency: involutional (senile), paralytic (neurogenic), cicatricial, mechanical, and congenital. [3]
Involutional ectropion
Involutional ectropion is the most common form of ectropion. A major factor is horizontal lid laxity, which is usually due to age-related (most patients are older persons) weakness of the canthal ligaments and pretarsal orbicularis.
For many years, physicians have questioned why some patients develop ectropion and others develop entropion, when both conditions seem to share the same etiologic factors. Bashour and Harvey answered this question, reporting the following [4] :
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Patients with involutional entropion have tarsal plates that are smaller than the normal average for age. Involutional entropion results from the vector mechanical effect of an atrophied or smaller than normal for age partially or fully disinserted tarsal plate being overcome by the normal or increased tone of the preseptal/pretarsal orbicularis muscle.
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Patients with involutional ectropion have tarsal plates that are larger than the normal average for age. Involutional ectropion results from normal or larger-than-normal for age tarsal plate vector mechanical effects overcoming the normal or decreased tone of the preseptal/pretarsal orbicularis muscle in combination with medial/lateral canthal tendon laxity.
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Patients with an anophthalmic socket may have involutional ectropion due to chronic pressure of the ocular prosthesis.
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Disinsertion of the capsulopalpebral fascia may lead to severe tarsal ectropion.
Paralytic ectropion
Paralytic ectropion may occur with seventh nerve palsy from diverse causes such as Bell palsy, cerebellopontine angle tumors, herpes zoster oticus, and infiltrations or tumors of the parotid gland.
Cicatricial ectropion
Cicatricial ectropion occurs from scarring of the anterior lamella by conditions such as facial burns, trauma, chronic dermatitis, or excessive skin excision (or laser) with blepharoplasty. Ectropion is not uncommon after orbital fracture repair with a transcutaneous approach. Less common causes of cicatricial ectropion include cutaneous T-cell lymphoma.
Mechanical ectropion
Mechanical ectropion may occur with lid tumors, such as neurofibromas, that evert the lower lid.
Congenital ectropion
Congenital ectropion is rare and usually involves the lower lid. The cause is often a vertical deficiency of the anterior lamella. Although congenital ectropion is rarely an isolated anomaly, it may be associated with blepharophimosis syndrome, microphthalmos, buphthalmos, orbital cysts, Down syndrome, and ichthyosis (collodion baby). Occasionally, cases of congenital ectropion are paralytic.
Pathophysiology
Causal factors leading to ectropion include horizontal laxity of the eyelid (universal), dehiscence of the lower eyelid retractors, vertical shortening of the anterior lamella of the eyelid, paralysis of the orbicularis oculi muscle causing loss of eyelid muscular tone, and neoplasia within the lower eyelid pulling or forcing the eyelid away from the globe.
A study by Michels et al indicated that risk factors for either entropion or ectropion of the eyelid include dehiscence of the eyelid retractors, presence of a "white line," orbital fat prolapse in the cul-de-sac, decreased excursion and increased distraction of the lower eyelid, and increased laxity of the eyelid (as measured by the snapback test). Eyelids with ectropion were reported to have less elasticity than those with entropion. [5]
Presentation
Patients usually present because of epiphora, ocular irritation, or cosmesis.
Generally, the progression observed is from eyelid laxity to punctal ectropion, to medial ectropion, and then to generalized ectropion. If the punctum is everted slightly from the lacus lacrimalis, tears cannot effectively drain into the canalicular system. Also, horizontal eyelid laxity may produce a flaccid canalicular syndrome or poor lacrimal pump so that tears are not siphoned from the lacus lacrimalis, producing epiphora.
This tearing malfunction is aggravated by the chronic ectropion and eyelid retraction that produce lagophthalmos and secondary exposure keratopathy. With time, the exposed conjunctiva thickens and keratinizes, producing further ocular irritation.
Indications
Tearing (epiphora) is probably the most common indication for surgical correction, but ocular irritation and cosmesis are also frequently encountered and may be indications for surgery.
Relevant Anatomy
The orbicularis oculi muscle is the sphincter of the eyelids. It spreads over the eyelids and out onto the forehead, temple, and cheeks. It is divided into orbital and palpebral portions, with the palpebral portion subdivided into preseptal and pretarsal parts.
The pretarsal part is attached laterally to the Whitnall tubercle by the lateral canthal tendon. This tendon (which is actually just a band of connective tissue) is weak in ectropion. Medially, the pretarsal orbicularis forms the anterior crus of the medial canthal tendon that inserts into the frontal process of the maxillary bone. The posterior pretarsal orbicularis inserts into the posterior lacrimal crest. The small strip of pretarsal muscle at the lid margin forms the gray line and is called the Riolan muscle. The images below demonstrate these relationships through horizontal and sagittal sectioning of the orbit.
Contraindications
Surgery to correct ectropion is contraindicated in patients who are unable to tolerate the procedure.
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Sagittal section through orbit.
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Horizontal section through orbit.
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Eyelid shortening by lateral tarsal strip fixation. (A) Pull the eyelid medially to prevent buckling of the lateral canthal tendon, and, with scissors, cut a lateral canthotomy to the orbital rim. Transect the inferior crus of the lateral canthal tendon. Grasp the lateral lid with forceps and pull it medially to confirm complete interruption of all attachments. (B) With fine pointed scissors, split the eyelid along the grey line for a distance of 5-10 mm, depending on the amount of lid shortening required. Continue the dissection to separate the anterior skin-muscle lamella from the posterior tarsoconjunctival lamella. (C) Cut the retractors and conjunctiva from along the inferior border of the tarsus beneath the split section. Cauterize the palpebral vessels, which are usually injured at this stage. (D) With fine scissors, remove a strip of marginal epithelium from the free portion of tarsus.
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Eyelid shortening by lateral tarsal strip fixation. (E) Lay the anterior surface of the flap over the flat face of a forceps handle for support, and scrape the conjunctival epithelium from the posterior surface of the tarsus with a scalpel blade. Cut off the remnant of the lateral canthal tendon from the bare tarsus to form a strip 3-4 mm wide and 4 mm long. (F) Pass two 4-0 Mersilene or Vicryl sutures on a small, stout, half-circle needle through the tarsal strip from outside to inside and then through the periosteum just inside the lateral orbital rim. To be certain a firm periosteal bite is achieved, pull up on the suture and observe the patient's head move slightly. Tie the sutures firmly. (G) With forceps, pull the skin-muscle flap laterally and excise the excess triangle with its marginal cilia. (H) Reform the canthal angle with an interrupted suture of 6-0 nylon. Close the orbicularis muscle with one or two 6-0 chromic sutures, and the skin with interrupted stitches of 6-0 nylon or silk.
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Medial spindle tarsoconjunctival resection. (A) Place a number 00 or 0 Bowman probe in the inferior canaliculus to mark its position, and evert the lower eyelid with forceps. (B) With a scalpel blade, cut a spindle-shaped segment 8-10 mm long and 4-6 mm high from the conjunctiva and tarsus. Locate the excision 4 mm below the inferior punctum, positioned so two thirds of the spindle lie lateral to the papilla. (C) Remove the bowman probe. Pass a double-armed 4-0 chromic suture through the inferior wound edge from inside the wound to the conjunctival surface. (D) Continue passing the same sutures through the superior wound edge from the conjunctival surface to the subtarsal space to form a double vertical mattress stitch.
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Medial spindle tarsoconjunctival resection. (E) Pass both needles anteriorly through the center of the spindle-shaped defect to emerge on the skin surface. (F) Tie the suture on the skin surface with enough tension to pull the wound edges together and to invert the lid margin and punctum.
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The modified "lazy-T" procedure. (A) Hold the lid margin with 2 forceps, and, with scissors, make a full-thickness vertical cut through the lid 4 mm lateral to the inferior punctum. Cauterize the marginal artery. (B) With forceps, grasp the 2 free tarsal edges and overlap them with moderate tension. On the lateral side of the wound, mark the amount of excess lid to be resected. (C) Cut along the mark with scissors to excise a V-shaped segment of full-thickness eyelid. (D) Evert the medial portion of the eyelid with forceps. Place a number 00 or 0 Bowman probe into the canaliculus to mark its location. Cut a horizontal V-shaped segment of conjunctiva and capsulopalpebral fascia 4 mm below the canaliculus. The excised wedge should measure about 5 mm vertically by 8 mm horizontally, and should have its broad base laterally, at the previously cut vertical eyelid defect.
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The modified "lazy-T" procedure. (E) Close the horizontal incision with several 6-0 plain or chromic gut sutures to shorten the posterior lamella. Bury the knots to prevent corneal abrasion. (F) Pass a 6-0 silk vertical mattress suture across the tarsal defect at the eyelid margin for alignment. Reapproximate the cut tarsal surfaces with several 6-0 Vicryl sutures, keeping them beneath the conjunctiva. (G) Place a second marginal 6-0 silk suture through the lash line. Tie the marginal sutures with enough tension to evert the wound edges slightly, and leave the suture ends long. Tie together the remaining tarsal sutures. (H) Close the orbicularis muscle with interrupted 6-0 chromic gut sutures and the skin with 6-0 nylon stitches. Tie the long ends of the marginal sutures to these stitches to keep them off the cornea.
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Anterior lamellar lengthening with skin graft.(A) Mark the line of incision 3 mm below the eyelid margin or along the upper edge of the contracted area of skin if nonmarginal. Extend the line at least 6-8 mm on either side of the contracted area. Place a traction suture of 4-0 silk through the marginal tarsus.(B) Cut along the marked incision line with a scalpel blade. Sharply dissect the skin from the underlying orbicularis muscle for a distance of 5-6 mm beyond all areas of contraction. When free, the eyelid margin should overlap the corneal limbus without tension by 1-2 mm. Obtain meticulous hemostasis with pressure or epinephrine-soaked gauze. Avoid excessive cautery.(C) Mark an incision line in the supratarsal eyelid crease of the ipsilateral or contralateral upper eyelid. Outline an elliptical segment, as for upper eyelid blepharoplasty. The width of the graft should be 1.5 times the width of the recipient bed defect.(D) Cut the donor skin along the marked line with a scalpel blade. Undermine the graft with scissors and dissect it from the orbicularis muscle. It may be necessary to excise part of the muscle to allow closure of the wound. Close the donor site with a running suture of 6-0 nylon.
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Anterior lamellar lengthening with skin graft. (E) An alternative donor site is retroauricular skin. Center the graft at the posterior base of the ear so that half extends onto the retroauricular skin and half onto the non–hair-bearing supramastoid skin. Mark the graft the appropriate shape and 1.5 times the width of the recipient defect. Cut the skin with a scalpel blade and dissect skin from subcutaneous tissue with scissors. Close the donor site with a running stitch of 4-0 Vicryl. (F) Remove all subcutaneous tissue from the skin graft with sharp dissection. If needed, trim the graft to fit the defect, keeping it 1.5 times the required width. (G) Suture the graft into the recipient bed using interrupted 7-0 Vicryl stitches. If the graft is larger than 2 cm in diameter, cut 1 or more stab incisions in its central portion for drainage. Place a 4-0 silk Frost suture through the eyelid margin and tape it to the brow to keep the eyelid closed and the graft flat. (H)Pass a 5-0 nylon vertical mattress suture through the skin beyond the graft edges centrally and put additional mattress sutures on either side. Place a Telfa pad soaked in antibiotic solution over the graft, and position a rolled sterile sponge over the pad. Tie the mattress sutures snugly to keep the graft immobile.
