Gregg T. Lueder
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.
CONGENITAL ANOMALIES OF THE EYELID
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.
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
Congenital ptosis usually results from under-development of the eyelid levator muscle. The condition may be bilateral or unilateral and may be isolated or associated with other ocular or systemic disorders. Unilateral ptosis is more likely to be isolated. Bilateral ptosis is more likely to be associated with other problems. Etiologies for bilateral ptosis include familial (usually autosomal dominant), chromosomal (eg, Turner syndrome), teratogenic (eg, fetal alcohol syndrome), and syndromic. Both bilateral and unilateral ptosis also frequently occur in otherwise normal children, in which case there is often no identifiable causative factor.
Ptosis presents with the upper eyelid resting in a lower position than normal on the eye. It may range from mild, with the eyelid 1 to 2 mm lower than normal, to severe, in which case the eyelid may cover the whole cornea. In congenital ptosis, the eyelid crease is usually absent, because the crease normally forms from fibers of the levator muscle (which is hypoplastic in these patients) attaching to the eyelid skin. The residual levator muscle in ptosis is also usually stiff, which may limit full closure of the lid.
In rare instances, children may have pseudoptosis. In this condition, the eye with the lower eyelid initially appears to be abnormal, but the asymmetry is actually due to proptosis (anterior displacement) of the contralateral eye, where the upper eyelid is somewhat retracted.
Approximately 5% of children with congenital ptosis have the Marcus-Gunn jaw-winking phenomenon. In this condition, the fibers that innervate the levator muscle are aberrantly connected to fibers that innervate the masseter muscle. This produces a synketic elevation of the eyelid during jaw movements. In infants, this is usually noted while they suck during feeding, and in older children, it can be seen by asking the child to move the jaw laterally. This usually manifests as a baseline ptosis with intermittent elevation or even retraction during jaw movements, but it may also manifest as a baseline normal eyelid position, with intermittent widening of the palpebral opening during jaw movement.
The primary visual problem associated with ptosis is amblyopia, which may occur for two reasons.2 First, if the eyelid margin rests at or below the pupil, it may interfere with vision. In unilateral cases, this may cause the child to favor the normal eye. Second, the mechanical weight of the eyelid may induce astigmatism (asymmetric curvature) of the cornea, creating a blur that also causes the child to favor the opposite eye. In mild cases (1 to 2 mm), ptosis usually does not produce any visual or appearance problems. In moderate cases (the ptotic lid is 3 to 5 mm below normal level), children will often adapt compensatory strategies to improve their vision. Once affected infants have adequate neck control, they often tilt their head back in order to look beneath the droopy eyelid (chin lift). In addition, children will often attempt to use the frontalis muscle to assist in lifting the eyelid, producing contraction of this muscle and, in unilateral cases, asymmetric elevation of the eyebrows (Fig. 589-1). In severe cases, in which the lid covers most of the cornea, there is a great risk of deprivation amblyopia, which may be irreversible if the ptosis is not corrected early.
Treatment of ptosis involves surgical elevation of the eyelids. Amblyopia treatment with patching and glasses for astigmatism is also often necessary. Severe ptosis needs to be corrected within the first few months of life due to the risk of amblyopia. Timing of surgery for moderate ptosis depends on the presence of amblyopia and compensatory head postures. If these are present, early surgery is indicated. If not, surgery is often delayed until age 4 to 5 years. Children with mild ptosis often do not require surgery.
Compared to the incidence of congenital ptosis, acquired ptosis is relatively uncommon in children, and the differential diagnosis is large. Acquired ptosis rarely presents as an isolated phenomenon, and an etiology can often be identified by the history and associated findings. Possible etiologies include myogenic, neurogenic, inflammatory, infectious, and mass lesions.
Myasthenia gravis is a myogenic disorder that results from antibodies directed against acetylcholine receptors, which may initially present with ptosis.3 This can occur in the neonatal period and should be considered in the differential diagnosis of congenital ptosis, but it more commonly presents at an older age. Historical features that suggest this diagnosis include worsening of the symptoms with fatigue and intermittent diplopia (due to involvement of the extraocular muscles). Diagnostic tests include electromyography and serum anticholinesterase antibodies, and administration of edrophonium or neostigmine can improve symptoms.
Another myogenic disorder that may initially present with ptosis is chronic progressive external ophthalmoplegia (CPEO). This is usually due to mitochondrial dysfunction that affects the levator and extraocular muscles. Sporadic and inherited forms occur, and the ocular findings of CPEO may be seen in several diseases associated with mitochondrial dysfunction. One of these is Kearns-Sayre syndrome, which is associated with CPEO, pigmentary retinopathy, and cardiac conduction abnormalities. Children with CPEO should be evaluated by a cardiologist.
Neurogenic causes of ptosis include third cranial nerve palsy and Horner syndrome. The third cranial nerve innervates the eyelid levator muscle, four of the six extraocular muscles, and the iris muscles that constrict the pupil. In a complete third nerve palsy, the eyelid is ptotic, the eye is turned out and down (because the only residual functioning extraocular muscles are the lateral rectus muscle, which pulls the eye out, and the superior oblique muscle, which pulls the eye down), and the pupil is dilated (Fig. 589-2). In certain conditions, only the superior division of the third nerve is involved, in which case only innervation of the eyelid and superior rectus muscle are involved, producing ptosis and downward deviation of the eye.
FIGURE 589-1. Child with ptosis due to Cornelia de Lange syndrome. The child is using the frontalis muscle to help lift the upper lid above the visual axis (note arched eyebrows). The child also spontaneously tips the head backward to help see under the droopy lids.
FIGURE 589-2. This child has a right cranial nerve III palsy. Note the ptosis, right exotropia, and right hypotropia. Although the child also had right mydriasis, both pupils have been dilated pharmacologically.
Horner syndrome (Fig. 589-3) results from interruption of the sympathetic pathway between the hypothalamus and the eye. Patients usually present with mild to moderate ptosis due to decreased innervation of Mueller’s muscle (an accessory eyelid-elevating muscle). Anisocoria (unequal pupils) is also present, with the pupil smaller on the affected side (due to decreased innervation to the pupil-dilating muscles in the iris). There may also be “upside-down ptosis” of the lower lid: a higher position of the lower lid due to a deficiency of its sympathetic innervation. Some patients may have decreased periocular sweating on the affected side, and patients with congenital Horner syndrome may have unequal pupil color (heterochromia).
Horner syndrome usually does not produce problems with vision. Its primary importance lies in identifying an underlying cause. The pathway for the series of neurons that are responsible for Horner syndrome begins in the hypothalamus, travels through the spinal cord to the thoracic vertebrae, ascends over the apex of the lung and along the internal carotic artery, and through the orbital apex to the eyelid and iris-dilating muscles. Horner syndrome in infants may be caused by torsion of the neck during a difficult delivery, but it is usually idiopathic and typically benign. Acquired Horner syndrome may be seen in patients who have had damage to the pathway following central line placement in the neck. Neuroblastoma is an important potential cause of acquired Horner syndrome. If an underlying cause is not apparent, evaluation includes magnetic resonance imaging studies of the abdomen (looking for tumors in the adrenal area), chest, neck, and head, and urine tests for vanillylmandelic acid.4
The remaining differential diagnosis for acquired ptosis is long and includes trauma (either direct trauma to the levator muscle or damage to the third cranial nerve), mass effects (including orbital tumors and vascular malformations), inflammation (of either the eyelid, levator muscle, or orbit), and infection.
LESIONS OF THE EYELID AND PERIOCULAR AREA
The most common mass lesion that affects the eyelid is a sty (hordeolum, chalazion). Meibomian glands are normally present in the upper and lower tarsus of the eyelid. They secrete oils at the lid margin that stabilize the tear film and protect the eye. If these glands become obstructed, the oil cannot be excreted and an inflammatory response is initiated. This can result in a localized, raised, erythematous lesion of the eyelid, often with a white center (hordeolum). Not infrequently, the initial inflammation may involve a larger portion of the eyelid. It may be difficult to distinguish this condition from preseptal cellulitis. If the lesion persists, it may evolve into a chronic firm nodule (chalazion). One treatment for sties is warm compresses once or twice a day, although this may be difficult to perform in toddlers. Baby-shampoo eyelash scrubs are particularly good at obtaining improved meibomian gland flow. Most stiess resolve in 1 to 2 weeks, sometimes with spontaneous drainage of the lesion. Chalazia can take several weeks to resolve. Topical antibiotics may be effective in reducing secondary overgrowth of coagulase-negative staphylococcus, but the mechanical treatments are more useful. If the lesions do not resolve, surgical incision and drainage may be indicated.
Children with chronic sties may have blepharitis. This is an inflammatory condition in which the meibomian glands become chronically obstipated. The eyelid margins are typically erythematous, and crusts may develop in the lashes (eFig. 589.3 ). This is much more common in older adults but may occur in children and is often chronic. Symptoms include ocular irritation, intermittent blurred vision due to disruption of the tear film, and recurrent sties. Treatment is the same as noted above for hordeola, although chronic baby-shampoo scrubs may be needed to reduce the incidence of symptoms, sties, and chalazia.
Capillary hemangiomas may present on the eyelids or in the orbit. These initially present within the first few weeks of life, grow rapidly during the first few months, and then stabilize. Most eventually regress by 4 to 5 years of age. These lesions are histologically benign, but they may produce amblyopia, either by causing the lid to block vision or by inducing astigmatism by pressure on the globe (eFig. 589.4 ). These lesions require early treatment in order to prevent vision loss. Treatment methods include topical, systemic, or direct injection of corticosteroids or, less commonly, surgical resection. Interferon is sometimes used in patients with extensive lesions (see Chapter 364).
Another common periocular mass that presents in the newborn period is an orbital dermoid cyst (Fig. 589-4). These lesions develop at the sites where the cranial bone sutures fuse during embryologic development of the skull, most commonly in the superolateral orbit. Dermoid cysts present as firm, slightly mobile, round, subcutaneous nodules. They are filled with keratinaceous material, which is very inflammatory if it extravasates into the surrounding tissue. Surgical resection of these lesions may be indicated in order to confirm the diagnosis and to prevent traumatic rupture with subsequent inflammation.
FIGURE 589-3. This child has a right Horner syndrome. Note mild right ptosis and right miosis. The child does not demonstrate “upside-down ptosis” of the lower lid.
FIGURE 589-4. Dermoid of brow.
The differential diagnosis for other orbital tumors that may present with proptosis or secondary eyelid changes is long and includes rhabdomyosarcoma, neuroblastoma, optic nerve glioma, and leukemia.
MISCELLANEOUS EYELID CONDITIONS
Two other eyelid conditions are important to be aware of. The first is lagophthalmos. In this condition, the eyelid is unable to close completely. The differential diagnosis for this includes seventh nerve palsy, intrinsic tightness of the eyelid structures that limits their ability to close fully, congenital eyelid anomalies (eg, eyelid coloboma), and inability to completely close the lid due to forward displacement of the globe (proptosis). Children with this condition are at risk for corneal scarring and infection due to chronic exposure. Normally, elevation of the eyeball occurs during eyelid closure (Bell phenomenon); this may protect the cornea by moving it up and under the eyelid. Initial treatment for lagophthalmos includes lubrication with ophthalmic ointment and sometimes requires taping the eyelids shut during sleep. If the condition does not improve and chronic corneal irritation is present, surgery may be required. Surgical options include partial apposition of the lateral eyelid margins (tarsorrhaphy) to decrease the exposed area of the cornea or implanting a metal weight in the upper lid to mechanically increase eyelid closure.
The second eyelid abnormality that is important to recognize is trichotillomania (traction alopecia). In this condition, which is a form of obsessive-compulsive disorder, patients manually pull out their eyelashes. Trichotillomania occurs most commonly in females ages 8 to 14 years. It is not unusual for patients to engage in the activity when others are not present, so the family may not be aware that it is self-induced, and patients often deny pulling on their eyelashes. The diagnosis is made by the absence of inflammatory eyelid skin changes and the irregularity of the eyelash findings. Usually there are areas of complete eyelash loss adjacent to unaffected areas, and the hair shafts themselves may be broken at various lengths (eFig. 589.5 ). Patients should be questioned regarding other obsessive-compulsive traits, and referral to a mental health specialist may be indicated.
THE LACRIMAL SYSTEM
A normally functioning tear film is important in maintaining vision. Tears continually flow over the eyes, carrying away debris and keeping the eye comfortable. The tear film itself is important in forming visual images. It is the first surface that refracts the light rays that will eventually focus on the retina. The tears are produced in the lacrimal gland, then flow across the eye by means of a pump effect of the blinking eyelids. They then drain into the lacrimal puncta, travel to the lacrimal sac via the canaliculi, and flow through the nasolacrimal duct into the nose.
NASOLACRIMAL DUCT OBSTRUCTION
Nasolacrimal duct obstruction (NLDO) is one of the most common ocular problems in infancy, affecting approximately 6% of infants.5 It is the result of incomplete opening of the distal nasolacrimal duct at the site where it enters into the nose at the inferior meatus below the inferior turbinate on the lateral intranasal wall. NLDO usually presents within the first few weeks of life, with symptoms of excess tearing and periocular discharge and crusting, particularly on the lower lid and its lashes. Most patients have both epiphora and discharge, but some have only one of these symptoms. The excess tearing occurs because the tears cannot drain properly and therefore flow onto the lids. Mild cases may simply give the eyelids a wet appearance, as if the infant is about to start crying. Patients with more pronounced blockage may have frank overflow tearing (epiphora). Crusting and discharge occur because of stasis of the tears in the lacrimal sac with precipitation of mucus, which normally is dissolved in the tears. Normal flora bacteria are usually present in the tears, but they do not produce infection, because they are rinsed through the lacrimal system into the nares. In the presence of NLDO, the moist, stagnant environment of the lacrimal sac pre-disposes to infection (dacryocystitis). This usually produces a low-grade, chronic infection, with intermittent episodes of mucopurulent discharge on the eyelids. This is often worst on awakening. More severe cases (particularly with mucoceles—see below) may have acute dacryocystitis, with erythema and swelling over the lacrimal sac.
Most infants with NLDO do not appear particularly irritated by the disorder unless the symptoms are severe. This finding is useful in differentiating NLDO from other disorders that cause epiphora in infancy. In most other conditions, the excess tearing results from ocular irritation, and infants often have symptoms of increased light sensitivity (photophobia), which manifests as squinting, eye rubbing, and apparent discomfort. The most important disorder in the differential diagnosis of NLDO is infantile glaucoma. In infants with glaucoma, increased intraocular pressure causes the eye to grow abnormally large, and the cornea often becomes edematous. Patients usually present with buphthalmos (enlarged eyes), corneal opacities, photophobia, and epiphora. Other entities that may present with epiphora include epiblepharon (see above), corneal lesions (including infection and foreign bodies), and some inherited retinal disorders.
The natural history of NLDO is one of spontaneous improvement, with more than 90% of cases resolving by 9 to 12 months of age. Therefore, the initial treatment should be conservative. If symptoms are mild, with only slightly increased tear lakes and minimal crusting, no treatment may be necessary. If patients have visible epiphora and significant crusts, management with lacrimal massage and topical antibiotics is appropriate. The goal of lacrimal massage is to compress the lacrimal sac and force fluid through the membrane obstructing the distal nasolacrimal duct. If lacrimal massage is recommended, it is important to demonstrate the proper technique to the patient’s caregivers. A finger should be placed at the inside corner of the eyelid (the medial canthus), where one can feel a horizontal rigid structure (the medial canthal ligament). Gentle pressure should be applied toward the underlying bone, thus compressing the top of the lacrimal sac that lies behind the ligament. Topical antibiotics are useful in managing patients with significant crusting; however, it is important for the physician and parents to recognize that antibiotics will not cure the obstruction but rather will temporize symptoms while waiting for spontaneous improvement. It is not uncommon for symptoms to recur when antibiotics are stopped and therefore may be needed repeatedly. It is very unusual for virulent organisms to be present in NLDO, so most antibiotics will be at least partially effective. Culturing the discharge is rarely necessary.
FIGURE 589-5. Left lower lid infected lacrimal sac mucocele.
Surgical treatment may be indicated if NLDO does not improve with age. Initial surgery involves passing metal probes through the lacrimal system from above, through the lacrimal sac, and into the distal duct. Some ophthalmologists perform this procedure in awake infants in their offices, but most probings are performed under general anesthesia. The initial surgery is effective in greater than 90% of infants.
Approximately 1% to 2% of infants with NLDO present in the first week of life with a blue-tinged mass called a mucocele (also known as amniotocele, dacryocele, or dacryocystocele) overlying the lacrimal sac (eFig. 589.6 ). The mass results from distention of the lacrimal sac, which does not occur in infants with typical NLDO. It is thought to occur due to a one-way valve effect of the upper lacrimal system, which allows fluid to enter but not exit the sac. Almost all affected patients have an associated intranasal nasolacrimal duct cyst below the inferior turbinate at the site where the duct normally exits. Mucoceles are prone to infection, which produces swelling and erythema of the lacrimal sac (Fig. 589-5).
If the mucocele is not infected, initial management with warm compresses and topical antibiotics may be appropriate, and some will improve spontaneously. However, some ophthalmologists prefer to proceed with surgical intervention before infection sets in. If the mucocele does not resolve or if it becomes infected, early treatment is indicated. The infection in patients with mucoceles is more severe than the typical low-grade dacryocystitis that occurs in children with typical NLDO and could potentially lead to sepsis. Mucoceles typically occur in the first month of life, when the infant is relatively immunocompromised. A combination of probing and endoscopic removal of the nasolacrimal duct cyst is highly effective.6
DECREASED TEAR PRODUCTION
Inadequate tear production is uncommon in infancy. This problem can be divided into two main groups. First, and very uncommon, is marked underproduction of tears (congenital alacrima). This may occur in conditions such as family dysautonomia (Riley-Day syndrome). The corneas in affected patients are at risk for scarring and infection, and children present with marked ocular irritation and redness, although symptoms and signs may not be present in infancy or the first few years of life. Aggressive treatment with ocular lubrication (and topical antibiotics, if needed) is indicated in these patients, who often have significant ocular problems.
A more frequent, but also uncommon, condition is lack of reflex tearing. In this condition, infants have normal basal tear production, which lubricates the eye and allows normal vision and ocular comfort. However, they do not produce reflex tears, which normally result from either ocular irritation (eg, due to a foreign body) or as an emotional response (ie, crying). Children with absent reflex tearing typically present in the first few months of life, because their caregivers note that they do not produce tears when they are crying. They have no symptoms of ocular irritation or conjunctival redness. Ophthalmic examination reveals a normal tear layer on the eyelid margin (indicating normal basal tear production), and there are no punctate irritation spots on the cornea. No treatment is needed for this condition.