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.
In this article:
- What is lagophthalmos?
- Symptoms of lagophthalmos
- Causes of lagophthalmos
- Facial nerve paralysis
- Cicatricial Lagophthalmos
- Nocturnal Lagophthalmos
- Incomplete Blink
- Diagnosing the cause of lagophthalmos
- Differential Diagnosis
- Are there any complications with lagophthalmos?
- Living with lagophthalmos
- Prognosis
- References
What is 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.
Facial nerve paralysis occurs in 30 to 40 people per 100,000 annually in the United States. The most common cause is Bell palsy and is responsible for up to 80% of cases. Bell palsy is an acute, unilateral facial nerve paralysis that resolves spontaneously over time. There is no known cause; however, it may have an association with viral infections.
Patients who are unable to blink and completely close their eyelids are at risk of drying out the outer layers of the eye, which eventually may cause blindness. This can progress to corneal ulcers and perforation.
It is essential to recognize the signs of lagophthalmos early and investigate the causes and begin treatment. The primary cause of lagophthalmos is facial nerve paralysis, which leads to paralytic lagophthalmos.
The purpose of treating lagophthalmos is to prevent further corneal exposure and to improve eyelid function. Any asymmetry in a person’s face will likely have a psychological impact. Medical treatment consists of improving the quantity, quality, and stability of the tear film.
Surgical procedures can be dynamic or static and focus on reestablishing eyelid function or eyelid coverage. The choice of treatment and reconstruction method will depend on the location, severity, etiology of lagophthalmos, as well as patient factors of age, health, and their expectations.
Symptoms of lagophthalmos
While there might be many symptoms associated with the actual cause of lagophthalmos, there are few symptoms that are alarming:
- Eye dryness
- Eyelid irritation and blepharitis
- Decreased vision or blurry vision
- Inability to blink
- Asymmetry of the eyelid and/or other facial muscles
In Bell’s palsy additional symptoms are:
- earache, hyperacusis, deafness,
- taste alterations,
- paresthesia of the cheek, mouth,
- eye pain, tooth ache
- asymmetry of the face, uneven mimics.
Causes of lagophthalmos
Eyelid movement is a complex mechanism that involves both conscious and subconscious muscle control. Whenever the eyelid does not close completely, there might be a serious underlying problem. Lagophthalmos is divided into subtypes based on the mechanism causing it.
Facial nerve paralysis
It may be caused by many factors. As facial nerve’s function is eyelid movement, any process affecting it will cause lagophthalmos:
Infection:
- Otitis (external, otitis media)
- Mastoiditis
- Viral (herpes simplex, herpes zoster, influenza, coxsackievirus, polio, mumps, mononucleosis)
- Bacteria (Tuberculosis, syphilis, leprosy, cat scratch disease, Lyme disease, botulism)
- Fungal (Mucormycosis)
Trauma:
- Facial injuries
- Birth trauma
- Fractures to the skull base, temporal bone fracture
Tumor:
- Primary nerve tumors
- Neurofibromatosis Type 2
- Brain tumors
Metabolic:
- Diabetes mellitus
- Hypertension
- Vitamin A deficiency
- Hyperthyroidism
Toxic:
- Thalidomide
- Alcohol excess
- Arsenic
- Tetanus/Diphtheria toxins
- Carbon monoxide
Iatrogenic:
- Post-immunization (Guillain-Barre syndrome)
- Medication side effect/toxicity
- Post-tonsillectomy/adenoidectomy
- Embolization
- Mandibular block anesthesia
- Botox injection
- Dental and maxillofacial surgery
- Eyelid cosmetic surgery
- Squint surgery (vertical muscle recession surgery)
Neurological:
- Millard-Gubler syndrome
- Foix-Chavany-Marie syndrome
Congenital:
- Mobius syndrome
- Goldenhaar syndrome
- Ichthyosis
- Hereditary hypertrophic neuropathy
- Melkersson-Rosenthal syndrome
Autoimmune:
- Bell’s palsy
- Amyloidosis
- Temporal arteritis
- Multiple sclerosis
- Myasthenia gravis
- Sarcoidosis
- Thrombotic thrombocytopenic purpura
Cicatricial Lagophthalmos
- Sunburn
- Chemical burn
- Ichtiosis
- Contact dermatitis
- Eyelid surgery
- Eyelid/eyelash chronic infection or parasitic infestation
- Pemphigoid and bullous inflammatory reactions
Nocturnal Lagophthalmos
Lagophthalmos, which occurs during sleep, is termed nocturnal lagophthalmos. It can cause symptoms of dry eyes and exposure (line) keratopathy. The diagnosis can be challenging if there is also a problem with eyelid inflammation or inversion.
The patient may not be aware of lagophthalmos during sleep. People may have associated insomnia, and eye dryness when waking up in the morning, or during the night. This condition is common.
Incomplete Blink
An incomplete blink may be an issue in patients with Parkinson disease and ocular myopathies, such as myotonic dystrophy and chronic progressive external ophthalmoplegia. This condition affects elderly people, and is caught by their relatives or caregivers. Usually, there are other neurological symptoms present, such as tremors or muscle weakness.
Diagnosing the cause of lagophthalmos
Diagnosis of the lagophthalmos is based on a careful history analysis and medical examination. One of the simple diagnoses is Bell’s palsy. This can be easily diagnosed by a primary care provider or an urgent care doctor. More frequently, the situation is so complicated that many specialists are involved:
- Neurologist
- Ophthalmologist
- Allergist-Immunologist
- Rheumatologist
- Maxillofacial surgeon
- Trauma surgeon
Imaging studies are important. A CT will show an infection or a fracture, while MRI is useful for the tumor diagnosis
Laboratory analysis can demonstrate an infection, autoimmune disease and drug overdose.
Differential Diagnosis
Lagophthalmos itself does not need a differential diagnosis, as it is mostly a symptom of other diseases. It is important for the doctors to find out what is the exact cause of the eye closing problem. Here the differential diagnosis is important and necessary.
A family history of the similar problem is a giveaway of the genetic syndrome. A pre-existing diagnosis of a thyroid disease or diabetes will explain the lagophthalmos in that situation.
Facial nerve (seventh cranial nerve) paralysis from any cause will result in lagophthalmos (without eyelid retraction). The more common etiologies include Bell palsy, sarcoidosis, cerebral ischaemic event, and post-surgical tumor excision.
Orbicularis oculi paralysis will lead to the unopposed action of the levator. For the lower lid, this will cause loss of tonus, which will result in a scleral show and a progressive ectropion. Epiphora (tearing) occurs due to lacrimal pump malfunction and increased reflex lacrimal secretion secondary to corneal exposure.
Are there any complications with lagophthalmos?
Complications can range from relatively mild, involving dry eye signs and symptoms, to corneal abrasions, persistent epithelial defects, ulceration, microbial keratitis, and corneal scarring. Corneal perforation can occur leading to visual loss. Band keratopathy can occur as a result of chronic exposure keratopathy.
Living with lagophthalmos
There are multiple challenges for patients with lagophthalmos with which to cope with. Patient education is vital to reduce complication risks with self-management regimes. These mainly consist of managing dry eyes, lid taping technique, and if due to facial palsy additional factors such as eating and drinking, speech, facial expression, and psychological impact. Providing patients with relevant educational material, and also directing them to support groups can be beneficial to patients’ wellbeing and outcome.
Prognosis
The prognosis of lagophthalmos depends on what caused it. For example, in Bell’s palsy the majority of patients have spontaneous recovery. If lagophthalmos is a complication of the infection, trauma or a tumor affecting the nerve, it will depend on the nerve recovery. In the situations with eyelid skin diseases a cosmetic surgery with grafting may be necessary, but might restore the function completely.