Ectropion

Etiology

Many factors may lead to the instability of the lower eyelid. The most common etiologic factor of lower eyelid ectropion is involutional change, caused by horizontal eyelid laxity and disinsertion of the lower eyelid retractors. This typically occurs from aging changes of lower eyelids and can be worsened by eye rubbing. Paralytic ectropion may occur with facial nerve palsy. With decreased innervation of the orbicularis muscle, the eyelid can become lax and floppy and can lead to poor protection of the globe. Cicatricial ectropion may be caused by scarring and shortening of the anterior lamella of the lower eyelid skin, which may also occur with aggressive lower eyelid blepharoplasty. Chronic sun exposure may also lead to these changes. Mechanical ectropion may be caused by a mass, such as a tumor, herniated fat, or edema of the lower eyelid, weighing down and pulling the lower eyelid outward.[1][5]

Epidemiology

The prevalence of involutional lower lid ectropion in elderly patients has been reported as high as 2%. It may be associated with trauma.

Morbidity is primarily associated with corneal/conjunctival exposure. [1]

History and Physical

A thorough history and physical is required to determine the etiology of lower eyelid ectropion. It is very important to understand if the patient had prior surgery, for example, lower eyelid blepharoplasty, or trauma or cancer excision and repair of the lower eyelid and/or cheek area. A proper history will help guide the clinician as to the etiologic factors and what to look for on examination. The patient should also be asked about any symptoms related to dry eye, eye rubbing, or instability of the eyelids. A full ophthalmic examination is necessary to properly assess the bilateral eyelids as well as the ocular surface and cornea to evaluation for any complications related to the ectropion.[1][6][7][8]

Evaluation

Lower eyelid ectropion leads to an abnormally positioned lower eyelid. On examination, the lower eyelid margin may appear low, with visualization of the lower cornea. Typically, the lower eyelid sits 1 mm to 2 mm above the inferior corneal limbus. With ectropion, the lower eyelid may also visually be outward. In extreme cases, the tarsal conjunctiva may be visible and may have signs of chronic conjunctivitis with keratinization of the conjunctiva. The eye may be injected, and in extreme cases leading to exposure keratopathy, the cornea may be dry with punctate epithelial erosions and possible ulceration. Eyelid laxity would also typically be apparent. One may check the distractibility of the lower eyelid by pulling the lower lid down and out to see how far the lid could be pulled. A snap-back test is performed by pulling the lid down and out and counting the number of seconds until the lid snaps back into position against the ocular surface. In extreme cases, blinking of the eyelids may be required to bring the eyelid back into position. During an examination, one would also thoroughly examine the periorbital region to rule out other causes such as cicatricial changes, such as chronic skin changes, or a mass. Examining the contralateral eyelid is also important since the etiology of the offended ectropic eyelid may also be leading to ectropion of the contralateral eyelid.[1][9][10]

Treatment / Management

Treatment typically begins with aggressive lubrication of the eyes with artificial tears, gels, and ointments. If the ocular surface is protected, then there is not an urgent need to protect the eyelid. However, if the ocular surface is compromised, for example in a patient with facial palsy, then the cornea can quickly decompensate, and scarring of the cornea can develop and lead to permanent vision loss.

Treatment is based on correcting the underlying etiology leading to ectropion. For example, with involutional changes, the lateral canthal tendon may be loose and disinserted. In this situation, a lateral tarsal strip surgical procedure may be performed with a lateral canthotomy and lower cantholysis to completely disinsert the canthus. Then a small wedge can be excised from the lateral lower eyelid. Then the lateral lower eyelid is reattached to the periosteum of the lateral orbital rim to reattach the lateral canthus back into position. By horizontally shortening the eyelid with this procedure and reattaching the canthus, the lower eyelid can be put back into proper position to protect the globe effectively. In cases of facial palsy, with the compromise of the orbicularis function, a lateral tarsal strip procedure may also be beneficial, as well as a lateral tarsorrhaphy to connect the lateral upper eyelid to the lateral lower eyelid.

In other cases, for example with cicatricial ectropion from aggressive lower eyelid blepharoplasty and excessive skin removal or scarring from chronic skin changes, the anterior lamella may be too short vertically. In these cases, it may be necessary to replace the skin, typically by using a full-thickness skin graft. One may use the ipsilateral or contralateral upper eyelid skin as a donor, if available, or pre-auricular or post-auricular skin may be used. It is not uncommon to perform a lateral tarsal strip in addition to a full-thickness skin graft in these cases. In cases of scar tissue formation leading to cicatricial ectropion, for example after trauma to the cheek, it may be necessary to dissect and free cicatrix formation to release the lower eyelid to allow it to go back into proper position. A temporary tarsorrhaphy or Frost tarsorrhaphy may be necessary to connect and elevate the eyelids during the initial healing phase after surgical repair.

It is common for the bilateral lower eyelids to have asymmetric but affected eyelids, for example with involutional ectropion, both lower eyelids may be affected, but to different extents. It may be necessary to perform a bilateral lower eyelid repair to improve both lower eyelids and to provide a symmetric result.[1]

Differential Diagnosis

• Basal cell carcinoma

• Bell palsy

• Floppy eyelid syndrome

• Ichthyosis

• Neuro-ophthalmic examination

• Neuro-ophthalmic history

• Squamous cell carcinoma, eyelid