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The eyelids play an important role in maintaining ocular health
and good vision. The mechanical action of the eyelids sweeping over
the globe brings in fresh, lubricating tears and removes debris.
The edge (margin) of the two upper eyelids and two lower eyelids
should be symmetric. The upper eyelid margin should rest at the
superior edge of the cornea or just over the superior iris, so as
not to block any visual input. The eyelid margins normally rest
against the globe, and the eyelashes are directed outward.
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Except for ptosis (drooping of the eyelids, blepharoptosis),
which will be discussed below, congenital anomalies of the eyelids
are rare. The most severe anomaly is cryptophthalmos, which presents
in the newborn with complete fusion of the eyelids. The underlying
eyeball is also usually malformed, and the visual prognosis is poor.
Eyelid coloboma is a discrete area in which eyelid tissue is missing,
most commonly on the upper eyelids, appearing as a notch or rectangular
defect of the margin where there will be no lashes. Anomalies of
the cartilage normally present inside the eyelid (tarsal plate)
or eyelid muscles may result in congenital entropion (in-turning
of the eyelid) or ectropion (out-turning of the eyelid). Congenital
tarsal kink is a severe variant of ectropion, in which the upper
eyelid appears to bend outward. Surgery for these conditions is
indicated if they produce corneal irritation (due to eyelashes rubbing against
the cornea in entropion) or exposure damage (due to inadequate corneal
cover and lubrication in ectropion). A relatively minor eyelid abnormality
is ankyloblepharon, which results from incomplete separation of
the eyelids during embryologic development. Infants usually present with
one or more fine strands of adherent tissue between the upper and
lower eyelids, with secondary inability to open the eyes (eFig. 589.1). This can usually be treated
successfully in the ophthalmologist’s office with simple
cutting of the tissue.
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Epiblepharon is a relatively common congenital eyelid anomaly.
It results from an extra fold of skin below the lower eyelid margin,
which may cause the eyelids and lashes to rotate in toward the eye
(eFig. 589.2). It is most commonly seen in
Asian children. If the lashes rub against the cornea, affected infants
may develop symptoms of ocular irritation, overflow tearing, and
excess mucus formation. The symptoms of this disorder may be confused
with those of nasolacrimal obstruction, and it is important to differentiate
these two entities by inspecting the eyelid margin. Epiblepharon
may spontaneously improve in the first 6 to 12 months of life, and
conservative treatment with topical lubricants may provide symptomatic
relief. If the condition does not improve, surgery to evert the
eyelid margin is usually successful.1
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