Lagophthalmos

Lagophthalmos 

Lagophthalmos describes the incomplete or abnormal closure of the eyelids. A full eyelid closure with a normal blink reflex is necessary for the maintenance of a stable tear film and healthy ocular surface. Patients who are unable to blink and completely close their eyes are at risk of corneal exposure, evaporation of the tear film, and subsequent exposure to keratopathy. This can progress to corneal ulceration and perforation. 

Types of Lagophthalmos

Blink Lagophthalmos

When the eyelids don’t fully close during a blink, this is called “blink lagophthalmos.” Blinking keeps the eyes lubricated by spreading the tear film evenly along the eyes’ surface. An incomplete blink can lead to dry spots on the eye and other uncomfortable dry eye symptoms. Colliding eyelashes or tasks that require a high level of focus (such as working on a computer) can contribute to blink lagophthalmos.

Nocturnal Lagophthalmos

Nocturnal lagophthalmos occurs during sleep, so people with this condition may be unaware they have it. One common cause of this type of lagophthalmos is a decrease in fatty tissue behind the eyeball. Less cushioning causes the eye to sink further into the socket, making it more difficult for the lids to completely close. The fatty tissue can deteriorate for several reasons, including the presence of an autoimmune disease.

Paralytic Lagophthalmos

Paralytic lagophthalmos results from a paralyzed cranial nerve, thus preventing the eyelids from complete closure. Paralysis of the seventh cranial nerve can be caused by Bell’s palsy, tumors, or trauma.

Iatrogenic lagophthalmos

This is when the eyes can’t fully close due to medical treatment. Medical procedures that can cause lagophthalmos include Botox injections and sutures near the eye.

Causes 

A variety of things can cause lagophthalmos, but they mostly fall within two categories.

The first is damage to the seventh cranial nerve, which controls the muscles in your eyelid. This is also known as the facial nerve. Many things can cause damage to the facial nerve, including:

• injury, either from blunt trauma or a deep cut
• stroke
• Bell’s palsy
• tumors, especially acoustic neuromas
• Möbius syndrome
• autoimmune conditions, such as Guillain-Barré syndrome

The second group of causes involves damaged eyelids, which can result from the following:

• scarring from burns, injuries, or certain medical conditions, such as Stevens-Johnson syndrome
• eyelid surgery
• floppy eyelid syndrome
• Protruding and sunken eyes can also lead to lagophthalmos

Symptoms

Symptoms of lagophthalmos include:

• Feeling like there’s something in your eye
• Burning or pain in one or both eyes
• Watery or dry eyes
• Open sores on the clear, protective surface of your eye (cornea)
• Eye infection
• Blurry vision
• Red eyes
• Light sensitivity
• Poor sleep

Diagnosis 

An eye care provider will diagnose lagophthalmos through a series of tests. They’ll likely:

• Ask you questions about health history.
• Ask you to close your eyes.
• Observe how forcefully you close your eyes.
• Measure your eyelids.
• Count how often you blink and notice how completely your eyes close during a blink.