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Entropion is a medical condition in which the eyelid folds inward.
Entropion is an inward turning of the eyelid margin and appendages such that the pilosebaceous unit and mucocutaneous junction are directed posterior towards the globe.
One of the most common eyelid malpositions.
There are four main categories of entropion, each with a different pathophysiology: involutional, spastic, cicatricial and congenital.
In a study of nearly 25,000 individuals over 60 years old, involutional entropion was found in 2.1% of patients.
Prevalence increased with age: 0.9% for patient 60-69 years old, 2.1% for 70-79, and 7.6% for those over 80.
Involutional entropion has a prevalence of 2.4% in whites and 0.8% in blacks.
Asians and females are more enophthalmic contributing to higher rates of entropion observed in these populations.
Patients with involutional entropion are often elderly and have significant comorbidities, with a 4-year mortality for patients with involutional entropion of 30%.
Orbital fat content and overall volume decreases with age or after trauma, producing enophthalmos.
Greater spacing between the globe and eyelid creates lid laxity.
Histologic examination of tarsal plates in patients with involutional entropion shows collagen degeneration, disorganized collagen fibers and abnormal elastogenesis.
Involutional entropion is due to loss of horizontal lid support, disinsertion, atrophy or dehiscence of lower lid retractors, preseptal orbicularis oculi ov2242ide, loss of vertical lid support with tarsal atrophy,and orbital fat atrophy leading to enophthalmos.
The lower lid derives stability from the orbicularis oculi, lower lid retractors, tarsus and canthal tendons.
The lower lid retractors provide vertical stability and are analogous structures to the levator aponeurosis and Mueller’s muscle in the upper lid.
The canthal ligaments and tarsal plate contribute horizontal lid stability.
Females have smaller tarsal plates than males, which explains in part why entropion is more prevalent in females.
Loosening of horizontal tension across these structures, especially the lateral canthal tendon, allows the lid margin to rotate.
Collagen fibers provide tensile strength to the tarsus, and elastic fibers give the tarsus resiliency.
With aging, the tarsus shifts from mainly collagenous fibers to elastic fibers, and the total number of collagen and fibers decreases.
This shift in the number of collagen fiber population is associated with increased horizontal eyelid laxity.
Horizontal lid laxity can be evaluated with the snap back test.
The examiner pulls the lower lid down and observes the lid returning to its original position without allowing the patient to blink.
Normally, the lid returns promptly without a blink, but in cases of increased laxity a blink may be needed to reestablish proper position.
The examiner can also pull the lower lid anteriorly away from the globe. In involutional entropion, the lower lid can be displaced 6-15mm from the globe, compared to only 2-3mm in the normal case.
Bilateral disease is three times more common than unilateral involvement.
More common in women, with prevalence 2.4%, than men, prevalence 1.9%.
Usually affects the lower lid.
With it the eyelashes continuously rub against the cornea causing irritation.
Usually caused by genetic factors.
Repeated cases of trachoma infection may cause scarring of the inner eyelid, which may cause entropion.
Can cause corneal and conjunctival damage leading to corneal stromal abrasion, scarring, corneal thinning and corneal neovascularization.
In advanced cases, there can be risk of corneal ulcer and perforation.
It can also cause secondary pain of the eye, scarring of the eyelid, or nerve damage.
The upper or lower eyelid can be involved, and one or both eyes may be affected.
It is most common in people over 60 years of age.
Symptoms of entropion include:
Redness and pain around the eye
Sensitivity to light and wind
Foreignness body sensation
Tearing
Sagging skin around the eye
Discharge
Epiphora
Epithelial erosions.
Decreased vision, especially if the cornea is damaged
Dry eye
Causes include:
Congenital
Aging
Scarring
Spasm
Trachoma can cause scarring of the inner eyelid, which may cause friction and entropion.
Trichiasis is a condition in which eyelashes grow in a posterior direction toward the corneal surface.
It can present similar to entropion, but management is different, as theproblem is the direction of lash growth and not a margin malposition.
Another diagnosis that can be confused with entropion is distichiasis, which is the growth of lashes from the meibomian gland orifices, which can irritate and damage the cornea.
Treatments are aimed specifically at the particular cause of the condition.
Treatments include lubrication to limit mechanical trauma, taping the lower lid to the malar prominence to correct lid margin position, or injecting low doses of botulinum toxin into the orbicularis to weaken the muscle and prevent ov2242ide.
Surgical therapy provides definitive treatment.
If there is mild disease with symptoms from lashes abrading the corneal surface, skin resection may be sufficient to rotate the margin.
Temporary relief can be achieved with taping of the lower lid to the malar eminence or with application of a cyanoacrylate liquid bandage to evert the lid margin.
Temporary relief from involutional entropion can also be achieved with botulinum toxin injections to the orbicularis, weakening the orbicularis to combat ov2242ide.
Due to its progressive nature and difficulty in managing the underlying condition, cicatricial entropion is considered the most difficult type of entropion to treat, with recurrence rate following surgery ranging from 12-71% regardless of technique used, with higher rates in more severe cases.
The most common complication following entropion repair is recurrence.
The transconjunctival involutional entropion repair has a recurrence of 3.3%.
Cicatricial entropion repair poses a more challenging treatment, and has a higher rate of recurrence.
Treatment of cicatricial entropion should always include medical control of the underlying pathologic condition when present.
Surgical management poses a challenge of lysing the scar tissue responsible for margin malposition.
Surgical technique depends on the severity of disease and etiology of symptoms.