The most common eyelid abnormality in children is ptosis (blepharoptosis), which causes
drooping of the eyelid. The upper eyelid normally rests just below the
junction of the cornea and sclera (the limbus) superiorly. Eyelid retraction is the opposite of
ptosis—the upper eyelid rests too high on the globe, such
that the sclera above the iris is visible. Lagophthalmos is present if the eyelids
do not close completely.
The eyelashes are normally directed away from the eye. Entropion is present if the eyelid
and lashes are directed inward. Ectropion is
present if the eyelashes are turned outward and the eyelid does
not rest directly against the eyeball. Distichiasis is
a condition in which patients have an extra row of abnormal eyelashes
on the posterior eyelid margin.
Abnormalities of the eyelid structures occur in association with
many craniofacial abnormalities. Examples of these include hypotelorism, in which the orbits and
eyelids are closer together than normal; hypertelorism,
in which these structures are farther apart than normal; and telecanthus, in which the distance
between the inner eyelid margins (medial
canthi) is abnormally wide. These abnormalities do not usually
cause vision problems, but analysis of the different relationships
of the eyelid structures may be useful in identifying specific syndromes. Epicanthal folds, extra medial eyelid
tissue, are fairly common in infants. They are the most common cause
of pseudostrabismus, the appearance of eye crossing despite normal
The upper eyelid is lifted by the levator
palpebrae superiorus muscle, which originates in the posterior
orbit. It travels forward and divides into an anterior portion,
the levator aponeurosis, and a posterior
portion, Müller’s muscle.
Both of these insert onto to the tarsal
plate (tarsus), the firm connective tissue that gives substance
to the eyelid (Figure 25–1). The levator aponeurosis has
attachments to the skin, which create the superior eyelid fold.
The levator muscle is innervated by the third cranial nerve. Müller’s
muscle is sympathetically innervated.
Cross-sectional view of upper eyelid anatomy.
The eyelids close by contraction of the orbicularis
oculi muscle, which is arranged in a circular configuration
around the upper and lower eyelids. It is innervated by the seventh
The eyelids initially form from ectoderm at 4 to 5 weeks gestation.
The upper and lower eyelids move toward each other and fuse at 10
weeks. Mesodermal tissue enters the lid and forms the musculature
of the eyelid. During the fifth month of gestation the eyelids separate.
Ptosis is caused by dysfunction of the levator muscle. In children
it may be congenital or acquired. Most commonly it is congenital,
secondary to underdevelopment of the muscle. Ptosis may be bilateral
or unilateral, and ...