出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/12/04 09:42:32」(JST)
Lagophthalmos | |
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Classification and external resources | |
Specialty | ophthalmology |
ICD-10 | H02.2 |
ICD-9-CM | 374.2 |
DiseasesDB | 32880 |
Lagophthalmos is defined as the inability to close the eyelids completely.[1]
Blinking covers the eye with a thin layer of tear fluid, thereby promoting a moist environment necessary for the cells of the exterior part of the eye. The tears also flush out foreign bodies and wash them away. This is crucial to maintain lubrication and proper eye health. If this process is impaired, as in lagophthalmos, the eye can suffer abrasions and infections. Lagopthalmos leads to corneal drying and ulceration.
Lagophthalmos can arise from a malfunction of the facial nerve.[2] Lagopthalmos can also occur in comatose patients having a decrease in orbicularis tone, in patients having palsy of the facial nerve (7th cranial nerve), and in people with severe skin disorders such as ichthyosis.
Today, lagophthalmos may arise after an overenthusiastic upper blepharoplasty.[3] Blepharoplasty is an operation performed to remove excessive skin overlying the upper eyelid (suprapalpebral hooding) that often occurs with aging. This can appreciably improve the patient's appearance, and make the patient look younger. If, however, excessive skin is removed, the appearance is unnatural and "lagophthalmos" is one of the signs of such excessive skin removal.
Nocturnal lagophthalmos is the inability to close the eyelids during sleep.[4] It may reduce the quality of sleep, cause exposure-related symptoms or, if severe, cause corneal damage (exposure keratopathy). The degree of lagophthalmos can be minor (obscure lagophthalmos), or quite obvious.
It is often caused by an anomaly of the eyelid that prevents full closure. Treatment may involve surgery to correct the malposition of the eyelid(s). Punctal plugs may be used to increase the amount of lubrication on the surface of the eyeball by blocking some of the tear drainage ducts. Eye drops may also be used to provide additional lubrication or encourage the eyes to increase tear production.
The condition is not widely understood; in at least one instance a passenger was removed from a US Airways flight because of it.[5]
Treatment of lagopthalmos can include both supportive care methods as well as surgical. If unable to receive surgery, artificial tears should be administered at least four times a day to the cornea to preserve the tear film.[6] Leading up to a surgery, a patient can undergo a tarsorrhaphy which partially sews the eye shut temporarily to further protect the cornea as the patient waits for care. Multiple surgical treatments exist for Lagopthalmos but the most prevalent method includes weighing the upper eyelid down by surgically inserting a gold plate.[7] Due to possible complications in conjunction with both the upper and lower eyelid, it might also be required to undergo a second surgery to tighten and elevate the lower eyelid to ensure both the upper and lower eyelids can fully close and protect the cornea.[6]
The name of the condition derives from the Greek λαγωός (lagoos, "hare"), referring to the myth that hares sleep with their eyes open.
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リンク元 | 「兎眼」「兎眼症」 |
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