Entropion is a common condition where the eyelid, typically the lower one, turns inward toward the eyeball. This mechanical issue causes the sensitive inner lining of the lid and the eyelashes to rub against the eye’s surface. Entropion is most frequently seen in older adults and necessitates medical attention because the constant friction can cause damage to the eye.
What is Entropion
Entropion occurs when the eyelid margin inverts, causing the lashes to make abrasive contact with the cornea and the conjunctiva. This continuous friction over the surface of the eye causes immediate symptoms. A common sign is the feeling that a foreign body, such as sand or grit, is perpetually stuck in the eye.
Uncomfortable symptoms result from this irritation. Excessive tearing, known as epiphora, is frequent as the eye attempts to flush out the perceived irritant. The eye also presents with redness, discharge, and sensitivity to light (photophobia).
Understanding the Causes
The reasons for the eyelid turning inward are classified into distinct etiologies, with the most common being age-related changes. This involutional or senile entropion occurs when the muscles and tendons supporting the eyelid weaken and loosen over time. It involves the horizontal laxity of the lower eyelid, disinsertion of the lower eyelid retractors, and the overriding action of the adjacent orbicularis oculi muscle.
Cicatricial entropion arises from scarring on the inner surface of the eyelid. This scar tissue formation can be caused by chemical burns, trauma, prior eye surgeries, or inflammatory conditions. The resulting contraction pulls the eyelid margin inward, often affecting both the upper and lower lids.
Spastic entropion is a temporary form caused by a spasm of the orbicularis oculi muscle, which closes the eyelid. This spasm is often triggered by acute ocular irritation, infection, or inflammation, sometimes following surgery. Congenital entropion is a rare occurrence present at birth due to abnormal eyelid development.
Treatment Options
Treatment for entropion depends on the underlying cause and the severity of the symptoms. Lubricating eye drops and ointments are used to provide moisture and a protective barrier over the cornea, mitigating friction from the lashes. Soft contact lenses can also be prescribed as a temporary corneal bandage to shield the eye surface from rubbing.
For a short-term fix, the eyelid can be manually repositioned and held in place using transparent skin tape applied to the lower lid and pulled toward the cheek. Temporary sutures, known as Quickert sutures, can be placed in the doctor’s office under local anesthesia to turn the eyelid outward. These temporary methods offer symptomatic relief while a patient awaits a definitive solution.
Botulinum toxin injections offer a non-surgical option, particularly for spastic entropion or as a temporary measure for involutional cases. The toxin is injected into the orbicularis oculi muscle, temporarily weakening its contraction and reducing the inward pull on the eyelid. The effects typically last only a few months, requiring repeated injections for sustained relief.
Surgical repair is the most effective and permanent correction for entropion, especially for involutional and cicatricial types. The goal of surgery is to restore the eyelid to its proper anatomical position by tightening or repositioning the supporting structures. For age-related entropion, procedures often involve tightening the horizontal laxity of the eyelid and reattaching the lower eyelid retractors, such as with a lateral tarsal strip procedure.
Potential Complications
Leaving entropion untreated allows the constant abrasion from the inward-turned eyelashes to cause progressive damage to the eye’s surface. An immediate risk is the development of a corneal abrasion (a scratch on the outer layer of the eye). Continuous friction can deepen this injury, leading to a corneal ulcer (an open sore on the cornea).
Corneal ulcers are serious because they can become infected, leading to severe pain and swelling. If the damage is extensive or if an infection is left unchecked, the resulting inflammation can lead to the formation of scar tissue on the cornea. This scarring can permanently impair vision, leading to irreversible vision loss in severe cases. Timely intervention is necessary to prevent these long-term medical risks.