Abnormalities of Eyelid Position and Function · (Fig. 1). The levator palpebrae superiorus muscle is the primary retractor (raises the eyelid and opens the eye) of the upper eyelid

EYELID ANATOMY

The opposing arches of the upper and lower eyelidsframe the ocular fissure. The eyelids are anchored at themedial canthus and lateral orbital tubercle by the canthaltendons. The eyelid protractor (e.g., muscle that closesthe eye) is the orbicularis oculi: a broad, flat, circumfer-ential muscle innervated by the facial nerve (CN VII)(Fig. 1). The levator palpebrae superiorus muscle is theprimary retractor (raises the eyelid and opens the eye) ofthe upper eyelid and is innervated by the oculomotornerve (CN III). This muscle has its origin at the orbitalapex and extends anteriorly adjacent and superior to the

superior rectus muscle. The distal portion fans out as thelevator aponeurosis, which inserts onto the anterior sur-face of the tarsus and into the upper eyelid skin to formthe eyelid crease.1 Muller’s muscle, a sympathetically in-nervated muscle, provides additional limited eyelid ele-vation. It has a short course in the upper eyelid arisingfrom the underside of the levator palpebrae superiorismuscle and inserting into the superior border of the tar-sus in the upper eyelid (Fig. 2).

The lower eyelid organization is similar to the up-per eyelid. The primary retractor of the lower eyelid isthe capsulopalpebral fascia. This fascial slip extendsfrom the inferior rectus muscle to insert along the infe-

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Departments of *Ophthalmology and †Otolaryngology, Wake Forest University School of Medicine/Baptist MedicalCenter, Winston-Salem, North Carolina.

Reprint requests: Dr. Martin, Wake Forest University Eye Center, Medical Center Boulevard, Winston-Salem, NC27157-1033.

Copyright © 2000 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA.+1(212) 584-4662. 0271-8235,p;2000,20,01,031,042,ftx,en;sin00046x.

ObjectivesOn completion of this article the reader will be able to list the differential diagnosis of ptosis and other eyelid abnormalities, including thosecaused by disorders of the third cranial nerve, the oculosympathetic pathway, the seventh cranial nerve, and the supernuclear pathways as wellas the neuromuscular disorders. The reader will also be able to recognize non-neurologic causes of ptosis, and know when to avoid unneces-sary neurological tests.

AccreditationThe Indiana University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to providecontinuing medical education for physicians.

CreditThe Indiana University School of Medicine designates this educational activity for a maximum of 1.0 hours in category one credit towardthe AMA Physicians Recognition Award. Each physician should claim only those hours of credit that he/she actually spent in theeducational activity.

DisclosureStatements have been obtained regarding the author’s relationships with financial supporters of this activity. There is no apparent conflictof interest related to the context of participation of the author of this article.

Abnormalities of Eyelid Position and FunctionTimothy J. Martin, M.D.* and R. Patrick Yeatts, M.D.*,†

ABSTRACT

Evaluation of the eyelids is an important part of the neuro-ophthalmic examination.Abnormal eyelid position and function can be caused by disorders involving the thirdcranial nerve, the oculosympathetic pathway, and the seventh cranial nerve, as wellas supranuclear pathways, or as a result of neuromuscular diseases. To avoid un-warranted neurological investigations, it is also important for the clinician to recog-nize non-neurological eyelid abnormalities (such as ptosis from levator dehiscenceor eyelid edema).

Keywords: Eyelids, blepharospasm, ptosis

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rior border of the tarsus in the lower eyelid and into theeyelid skin creating the lower eyelid crease. The inferiortarsal muscle in the lower lid is sympathetically inner-vated, and is analogous to Muller’s muscle in the upperlid (Fig. 2).

The eyelid can be divided anatomically into an an-terior lamella, comprised of skin and the orbicularisoculi muscle; middle lamella, containing the retractormechanism of the eyelid and the orbital septum; and theposterior lamella, comprised of tarsus and conjunctiva.The orbital septum arises from the periosteum at the or-bital rim (arcus marginalis) and compartmentalizes peri-ocular structures into preseptal and postseptal (orbital)anatomic regions (Fig. 2).

Eyelid anatomy may vary according to race andgender. The upper eyelid crease in women is oftenhigher (a greater distance from the lid margin) than inmen.2

The oriental eyelid has a low or absent upper eyelidcrease resulting from the absence of fusion of the orbitalseptum and the levator aponeurosis. Orbital fat(preaponeurotic fat pad) extends inferiorly, anterior tothe tarsus. The lower eyelid may also have absent lidcrease or a crease close to the origin of the lashes.3

EXAMINATION TECHNIQUES

Table 1 summarizes the important components ofexamining the eyelids, with more detailed explanationsin the text below.

Figure 1. Orbicularis muscle and adjacent muscula-ture. The frontalis muscle (A), superciliary corrugatormuscle (B), and procerus muscle (C), are identified. Theorbicularis muscle is divided into orbital (D), preseptal(E), and pretarsal (F) portions, and is anchored by themedial (G) and lateral (H) canthal tendons. (Courtesy ofBeard C. Ptosis. 3rd ed. St. Louis: The C.V. Mosby Com-pany; 1981, Figure 2.2.)

Figure 2. Eyelid anatomy, saggitalview. (Courtesy of Tenzel RR. Surgeryof acquired lid malpositions. In: JaffeNS, ed. Atlas of Ophthalmic Surgery.New York: Gower Medical Publishing;1990, Figures 6.2 and 6.9.)

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RECORDING EYELID POSITIONIN PRIMARY POSITION

The normal position of the upper eyelid in primarygaze is about 1 to 2 mm inferior to the superior limbus(the junction of the white sclera and clear cornea). Theposition of an eyelid can be recorded as the distance inmillimeters from this idealized position (millimeters ofptosis or retraction). Alternatively, the distance in mil-limeters from the center of the corneal light reflex andthe lid margin, the so-called margin-light reflex (MLR)distance can be used also as a measure of eyelid position

(Fig. 3). The lower eyelid normally rests at the inferiorlimbus. Like the upper lid, the lower lid can be retracted,or even ptotic (rising to narrow the fissure).4,5

ASYMMETRIC FISSURE HEIGHT

The distance between the upper and lower eyelid atits greatest vertical height is the palpebral fissure height.This measurement has the advantage of being more eas-ily measured than millimeters of ptosis or MLR, but pro-vides less specific information as it does not specify the

ABNORMALITIES OF EYELID POSITION AND FUNCTION—MARTIN, YEATTS

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Table 1. Evaluation of Eyelid Position and Function

Exam Examples ofComponent Method of Measurement Abnormalities

Observe Record as mm of ptosis (or A Horner’s syndromeeyelid retraction) from the normal typically causes only position position of the lid, or the 1–2 mm of ptosis; the

margin-to-light reflex (MLR), degree of ptosis maywhich is the distance of the be highly variable inupper lid from a central cornea myasthenialight reflex (see Figure 3)

Evaluate Measure upper eyelid excursion in Levator function islevator mm from extreme down-gaze to normal in levatorfunction extreme up-gaze, with the brow dehiscence, but usually

fixed by the examiner’s hand to poor in congenitalprevent any contribution from the ptosis, myasthenia, orfrontalis musculature (see Figure 4) third cranial nerve

paresisLook for lid Present when there is failure of Common in congenital

lag the upper lid to follow the ptosis, also confirmsdownward excursion of the eyeball true lid retraction

Measure lid Distance from the lid margin to Absent crease orcrease the major upper eyelid crease, increased distance

formed by a portion of the suggests levatorlevator insertion dehiscence

Evaluate An inability to fully close the Orbicularis weaknessorbicularis eye suggests weak orbicularis from facial palsies canfunction; oculi, (or restriction of result in corneallook for retractors) ulceration and lagophthalmos blindness

Observe Concurrent motility disorders may suggest a third-nerveocular palsy, orbital Graves’ disease, or myasthenia gravismotility

Observe Anisocoria: ptosis with a small pupil suggests anpupils oculosympathetic paresis (Horner’s syndrome), whereas ptosis with a

large pupil may occur with third cranial nerve palsies

Figure 3. Measuring eyelid position.(A) Millimeters from ideal position. Theupper eyelid normally rests about 2 mmbelow the superior limbus. Measuringfrom this ideal position, millimeters ofptosis or retraction can be determined.(B) Margin to light reflex distance(MLR). A positive number represents aneyelid above the light reflex, and a neg-ative number below the light reflex. (C)Palpebral fissure height. This measure-ment is the easiest to perform, but doesnot identify the actual position of theeyelids on the globe.

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actual position of the eyelid relative to the globe (Fig. 3).The size of the ocular fissure is the net result of forcesopening the eye (eyelid retractors), and those closing theeye (eyelid protractors). Thus, an ocular fissure that isabnormally narrow may be the result of a retractor weak-ness (ptosis), or protractor hyperactivity (orbicularisspasm). A palpebral fissure that is abnormally wide canresult from retractor hyperactivity (such as lid retractionin Graves’ disease) or protractor weakness (acute facialpalsy) (Table 2).

It is not always obvious which eye is abnormalwhen there is an asymmetry of the palpebral fissures.Does the eye with the smaller fissure have eyelid ptosis,or does the opposite eye have eyelid retraction? Further-more, ptosis on one side may cause a contralateral lid re-traction because the effort generated to lift the ptotic lidis shared bilaterally. This form of lid retraction promptlyreverses when the examiner gently lifts the ptotic lid.

MEASURING EYELID FUNCTION

The function of the levator papebrae superiorismuscle is determined by the measurement of eyelid ex-cursion from the extremes of down-gaze to up-gaze withthe brow immobilized (Fig. 4).

Lagophthalmos is the inability of the lids to closecompletely. Weakness of the protractor (orbicularisoculi) or restriction of the retractor (levator papebrae su-perioris) may cause lagophthalmos. Cranial nerve VIIparalysis with weakening of the protractor muscles typi-cally causes a profound lagophthalmos. Poor compli-ance of the levator muscle such as seen in congenitalptosis, Graves’ disease, trauma, or following surgical re-section of the levator papebrae superioris muscle, areother potential causes.5

A patient who displays lid lag will have a higher rest-ing position of the eyelid in relation to the eye in down-gaze when compared to primary gaze (the eyelid “lags”behind the eye in down-gaze). Lid lag is often seen inGraves’ disease, and is the result of the decreased elastic-ity of the levator muscle secondary to muscle fibrosis orinfiltration. Lid lag is also a characteristic of congenitalptosis, but not typical of most forms of acquired ptosis.

OTHER OBSERVATIONS

A high, asymmetric, or absent lid crease is a sign ofthe loss of attachment of the levator aponeurosis to thetarsus and skin (levator dehiscence), or may occur whenlevator function is poor. Ptosis and a motility distur-

bance may be observed in oculomotor paresis, myasthe-nia gravis, chronic progressive external ophthalmople-gia, or Duane’s syndrome. Congenital ptosis may be as-sociated with superior rectus dysfunction or MarcusGunn jaw winking phenomena. A large pupil on the sideof the ptosis may indicate a CN III palsy or post-traumatic ptosis associated with iris sphincter injury;and a miotic pupil on the side of the ptosis may indicatea oculosympathetic paresis. A mass in the lacrimal glandmay give an “S-shaped” deformity to the eyelid. Inspec-tion of the conjunctival fornices and gross palpation ofthe orbit for orbital masses should be performed on allpatients who present with ptosis.6

Protractor function should also be assessed. An in-complete blink or subtle flattening of the nasolabialgroove may indicate CN VII weakness. Orbicularisstrength can be estimated by having the patient closetheir eyes tight while the examiner attempts to manuallyopen them. Raising the brows to wrinkle the forehead,


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Table 2. Causes of Ocular Fissure Abnormalities

Observation Possible Causes

Ocular fissure too narrow Ptosis (retractor weakness)Orbicularis overaction

(“pseudoptosis”)Ocular fissure too wide Eyelid retraction (retractor

overactivity)Orbicularis weakness

Figure 4. Measuring eyelid function. A ruler is placedperpendicular to the central upper eyelid margin, with thethumb or hand placed to immobilize the brow. The fullexcursion of the eyelid margin from extreme downgaze to extreme upgaze is measured. Less than 10 mm isabnormal. D

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puckering the lips, and smiling to show teeth further testfacial motor function.5

CAUSES OF ABNORMAL EYELIDPOSITION AND FUNCTION

PTOSIS

Ptosis, or more precisely blepharoptosis, describesan abnormally low resting position of the upper eyelidbecause of levator insufficiency. The many causes ofptosis are outlined in Table 3, and described in more de-tail below.7,8

Neuropathic

OCULOMOTOR PALSY. The oculomotor nuclearcomplex consists of several subnuclei clustered togetherin the dorsal mesencephalon. Most of the third cranialnerve subnuclei are paired, parasaggital motor nuclei.However, innervation to the right and left levator mus-cles originates in a single midline subnucleus—the cen-tral caudal nucleus. Thus, ptosis occurring from lesionsaffecting the third nerve nuclear complex will be bilat-eral. Although most lesions in this area usually affectother third nerve functions, isolated bilateral ptosis canoccur.9

Fibers serving the levator muscle course with theother components of the oculomotor nerve to the orbit,travelling with the superior division of the oculomotornerve (with superior rectus fibers) to innervate the leva-tor palpebrae muscle. Ptosis occurring from lesions af-fecting the oculomotor nerve (such as a posterior com-municating aneurysm) is invariably associated withother signs of third nerve dysfunction.

OCULOSYMPATHETIC PARESIS (HORNER’S SYN-DROME). The oculosympathetic pathway takes a cir-

cuitous, multisynaptic route from the brain to the orbit,eventually innervating Muller’s muscle and the pupillarydilator muscle in the iris. Thus, lesions of the sympa-thetic pathway produce ptosis and relative miosis. How-ever, given the limited action of Muller’s muscle, theptosis never exceeds 2 mm. The lower eyelid may alsobe affected, resting at a higher position on the globe thanthe unaffected eye (“upside-down ptosis”).

SUPRANUCLEAR PTOSIS. Rarely, unilateral or bi-lateral ptosis can be the result of supranuclear lesions. Ex-tensive lesions involving the nondominant (usually right)hemisphere can cause bilateral, often asymmetric corticalptosis, invariably associated with other neurological dys-function. Unilateral cortical ptosis is rare and poorly un-derstood, but is reported to occur with focal hemisphericlesions ranging from the frontal to the temporal lobes.

Lesions involving the limbic (extrapyramidal) path-ways do not typically affect the resting position of theeyelid, but may cause apraxia of eyelid opening.10 Thistransient inability to open the eyelids is the result of inhi-bition of the levator (not orbicularis activation), and canbe a component of progressive supranuclear palsy,Parkinson’s disease, and other disorders.5

SYNKINETIC SYNDROMES. A number of congeni-tal synkinetic syndromes can cause transient ptosis byinhibition of the levator muscle, as outlined in Table 4.

NeuromuscularOCULAR MYASTHENIA. Myasthenia gravis is a

disorder of the neuromuscular junction that commonlycauses ptosis and diplopia. The disease may affect theocular muscles only (ocular myasthenia), or may causesystemic weakness. Clinical characteristics include vari-able weakness and worsening of symptoms with fatigue.Symptoms may be minimal or absent on arising fromsleep, and are usually worse late in the day.

Ptosis is present in many cases. The classic historyof an alternating ptosis, in which a ptosis “switchessides” should be considered myasthenia until provenotherwise. The ptosis can often be seen to worsen duringthe examination, especially with prolonged up-gaze(Fig. 5). Cogan’s lid twitch sign is often present, but isnot entirely specific for myasthenia. This finding isevoked by a rapid saccade from down-gaze to primaryposition, and consists of an initial overshoot of the uppereyelid, with slow downward return. Orbicularis oculiand other facial muscle weakness is common.

In some cases, variability is only evident betweenexaminations, underscoring the importance of carefuland accurate measurement of eyelid position and ocularmotility on each encounter. Examinations later in theday, when the patient is more fatigued, are usually moreproductive than early morning visits. Because myasthe-nia can produce virtually any motility pattern and/or pto-sis, it should be included in the differential diagnosis ofevery patient with ptosis and ocular motility disorders.5

The short-acting anticholinesterase drug edropho-nium chloride (Tensilon®, ICN Pharmaceuticals, Inc.,Costa Mesa, CA) is used in a diagnostic test for myas-thenia gravis—the “Tensilon test.” The agent only lasts a


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Table 3. Differential Diagnosis of Acquired Ptosis

NeuropathicOculomotor nucleus/fascicles/nerve palsyOculosympathetic paresisSupranuclear ptosis

Neuromuscular junctionMyasthenia GravisBotulism

MyogenicMyotonic dystrophyCPEO

Aponeurotic (levator dehiscence)Involutional ptosis (“senile” ptosis)Contact lens wearPostedemaTrauma

MechanicalDermatochalasisEyelid tumors

“Pseudoptosis”Obicularis activation (blepharospasm, etc.)Globe retraction

Duane’s retraction syndromeEnophthalmos

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matter of minutes, so the motility disturbance or ptosisneeds to be significant enough to allow confident appraisalof improvement over just a few minutes of observation.Reversal of ptosis is easily observed, but motility patternsmay be more difficult to assess, especially if subtle.

BOTULISM. Botulism is a neurological disordercaused by ingestion of food contaminated with Clostrid-ium botulinum. This bacterium elaborates botulinumtoxin, a powerful neurotoxin that blocks the release ofacetylcholine at the neuromuscular junction and de-stroys nerve endings. Ocular signs include ptosis, oph-thalmoparesis, and dilated pupils. Systemic symptomsinclude dizziness, headache, dysphagia, and weakness.Surprisingly, only a third of patients with ingestion ofbotulinum toxin have gastrointestinal symptoms.5

CPEO AND MUSCULAR DYSTROPHIES. Chronicprogressive external ophthalmoplegia (CPEO) is clini-cal designation describing symmetric, slowly progres-sive bilateral ptosis and limitation of eye movements.This clinical entity can occur as the result of a numberof different disorders, most of which are heritable, andmany that are associated with systemic signs andsymptoms.

Mitochondrial myopathies are a group of systemicdisorders that cause muscular weakness and CPEO as aresult of mitochondrial dysfunction. In addition to ptosisand ophthalmoplegia, mitochondrial myopathies fre-quently demonstrate weakness of facial and systemicmuscles, cardiac conduction abnormalities, pigmentaryretinopathies, and other systemic signs. Kearns–Sayresyndrome is a type of mitochondrial myopathy present-ing as CPEO that is recognized as a distinct syndrome,often diagnosed before age 20. It is caused by a mito-chondrial chromosomal defect, and is associated withcardiac conduction defects (including heart block andsudden death).

Myotonic dystrophy is a systemic myopathy that isa rare cause of bilateral ptosis and limited ocular motil-ity. Additional ocular signs include a characteristic“polychromatic” cataract and macular and retinal


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Table 4. Synkinetic Syndromes Affecting the Palpebral Fissure

PrecipitatingObservation Mechanism Disorder Movement Cause

Palpebral Inhibition Paradoxical With Congenitalfissure of levator levator adduction oculomotornarrows inhibition or abduction miswiring

Inverse Movement of Trigeminal-Marcus Gunn jaw to opposite oculomoter

phenomenon side (external synkinesispterygoid)

Activation of Aberrant Facial Aberrant facialorbicularis regeneration movement motors fibers

of the facial innervatingnerve orbicularis

musclePalpebral Activation Paradoxical With Congenital

fissure of levator levator adduction oculomotorwidens excitation or abduction miswiring

Marcus Gunn Movement of Trigeminal-phenomenon jaw to oculomoter

opposite synkinesisside (externalpterygoid)

Figure 5. Variable ptosis with ocular myasthenia. A 64-year-old woman presented with ptosis of the right upperlid. (A) Ptosis at the start of the examination. (B) Aftersustained up-gaze, the amount of ptosis has increased.(C) With additional fatigue, the ptosis is nearly compete.(D) After resting with her eyes closed for 5 min, theamount of ptosis is much less.

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pigmentary changes. Electromyography is diagnostic,demonstrating characteristic myotonic discharges(“dive-bomber” discharges). Visible (and palpable)wasting of the temporalis muscles is characteristic.5

Oculopharyngeal dystrophy is an heritable (autoso-mal dominant) condition affecting patients of French–Canadian ancestry in their fifth and sixth decade,causing progressive ptosis, limited ocular motility, andweakness of the bulbar musculature with dysphagia.

Congenital Ptosis

Congenital ptosis refers to a developmental abnor-mality of the levator papebrae superioris muscle, whichresults in ptosis. Ptosis may be unilateral or bilateral andmay occur sporatically or may be a component of an in-herited syndrome (e.g., the autosomal dominant ble-pharophimosis syndrome).

Congenital ptosis may be mild (2 mm), moderate (3mm), or severe (>4 mm). The more severe the ptosis, theless striated muscle is present to lift the eyelid, and thepoorer the levator function. A severe congenital ptosis iscommonly associated with fair to poor levator function(eyelid excursion of 6 mm or less), and a poor eyelidcrease.8

In congenital ptosis the levator palpebrae superiorismuscle contains more fibroblasts than muscle fibers, re-sulting in poor contraction and relaxation. Therefore, lidlag in down-gaze is a characteristic feature of congenitalptosis, not present in most acquired forms of ptosis.7 Thepresence of lid lag also explains why children with eitherunilateral or bilateral congenital ptosis develop a headposition (with chin up) to maintain unobstructed vision.

Involutional Ptosis

Involutional ptosis (also called “senile” ptosis) isthe result of age-related changes in the levator aponeuro-sis or levator muscle, and is the most common type ofptosis encountered in clinical practice.8

Aging and other factors can cause the levatoraponeurosis to become stretched, thinned, or detachedfrom its insertion at the tarsus and skin of the upper lid.This results in ptosis, but with normal levator function(excursion). The upper eyelid crease is typically ele-vated or absent, reflecting loss of the levator insertion.7Other factors such as contact lens wear,11 recurrenteyelid edema, topical steroid use, and trauma are othercommon causes of levator dehiscence that may occur inyounger patients12,13 (Fig. 6).

Surgery is generally successful in correcting invo-lutional ptosis, and is often used when the eyelid blocksthe superior visual field or for cosmetic reasons.

Other Causes

Blunt orbital trauma can cause a profound ptosis,but will often spontaneously resolve. Periocular traumathat results in a horizontal laceration of the eyelid fre-

quently involves the levator aponeurosis, and may re-quire a surgeon experienced in eyelid repair.

Periocular tumors cause ptosis by a mechanicalmeans or by affecting levator muscle function. A plexi-form neurofibroma, for example, may mechanically limitlid excursion by its sheer bulk or may infiltrate the leva-tor muscle, reducing its function. Contour abnormalitiesare often seen with tumors extrinsic to the levator muscleand limit eyelid excursion in sectorial fashion.

Pseudoptosis

Patients with marked dermatochalsis may have pro-lapse of the skin of the upper lid over the eyelid margin,simulating a ptosis (Fig. 7).

Globe retraction such as observed in Duane’s syn-drome or traumatic enophthalmos may be misinterpretedas ptosis. In these cases, the palpebral fissure is nar-rowed due to retraction of the globe into the orbit.

Patients who feign ptosis (functional or nonorganicptosis) will demonstrate an increase in orbicularis toneaffecting the upper and lower lids that cannot be sus-tained indefinitely.


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Figure 6. Elevated lid crease in aponeurosis dehis-cence. A 27-year-old man was referred to evaluate a pos-sible neurological cause for unilateral ptosis. There wasno associated motility disturbance (to suggest a third-nerve paresis), anisocoria (to suggest a Horner’s syn-drome), or variability (suggesting myasthenia). The pa-tient was a contact lens wearer for many years. Thepresence of an elevated eyelid crease (pictured) withnormal levator function confirmed levator dehiscence asthe cause of ptosis. (Courtesy of Martin TJ, Corbett JJ.Requisites in Neuro-ophthalmology. St. Louis: Mosby;2000, Figure 7.8.)

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ORBICULARIS OVERACTION:FACIAL NERVE HYPERACTIVITY

Lesions involving the facial nerve or its supranu-clear pathways can produce irritative states causing over-activity, including blepharospasm, hemifacial spasm,and other abnormal activation.14,15 Orbicularis activationnarrows the ocular fissure, but can usually be distin-guished from ptosis as increased orbicularis tone in theupper and lower lids is usually clinically evident.

Blepharospasm

Benign essential blepharospasm (BEB) is an idio-pathic condition in which there is intermittent spasm ofthe orbicularis oculi bilaterally, thought to be related todysfunction of the basal ganglia and extrapyramidal(limbic) system. These unwanted spasms of eye closurecan severely disable patients, making activities such asdriving, ambulating, and reading difficult or impossible.This condition is most common in patients in the fourththrough sixth decades.16 When blepharospasm is associ-ated with other facial movements, such as grimacing or torti-retrocollis, the condition is called Meigesyndrome.17

Secondary blepharospasm can be caused by ocularsurface disease or intraocular inflammation, and rarelyfrom meningeal irritation associated with intracranial le-sions. Blepharospasm can be a manifestation of tardivedyskinesia, resulting from neuroleptic drugs, and can oc-

cur in extrapyramidal disorders such as Parkinson’s dis-ease, Huntington’s chorea, and basal ganglia infarction.

Local injection of botulinum toxin (Botox®, Aller-gan, Inc., Irvine, CA) into the orbicularis oculi toweaken the muscle is an effective treatment for ble-pharospasm. Repeat injections are necessary, as the ef-fect lasts only several months at best.18,19 Surgical pro-cedures to weaken the facial nerve or to remove theorbicularis oculi muscle are complex and fraught withcomplications.

Hemifacial Spasm

Hemifacial spasm is intermittent spasm involvingthe upper and lower face on one side. Facial nerve func-tion is otherwise normal. This condition is most likelycaused by irritation and intermittent compression of thefacial nerve by the anterior inferior cerebellar artery orother branches of the basilar artery in the subarachnoidspace.20 Patients with typical, isolated, long-standinghemifacial spasm may not require neuroimaging. How-ever, patients with hemifacial spasm who also have fa-cial weakness must have neuroimaging (preferably mag-netic resonance imaging with GAD), as this combinationof signs is suggestive of a compressive lesion such as acerebellopontine angle tumor.21

Hemifacial spasm can usually be distinguishedfrom facial tics, as tics can be suppressed voluntarily fora period of time and typically begin in childhood. Focalepilepsy involving the face is rare and is typically fol-lowed by postictal facial paralysis (Todd’s paralysis).

Medical treatment of hemifacial spasm has in-cluded baclofen, carbamazepine (Tegretol®, Ciba-GeigyCorp., Summit, NJ), clonazepam, and more recentlyNeurontin, but these medications are rarely helpful. Aswith blepharospasm, botulinum toxin injection is ofteneffective.22 Neurosurgical exploration of the root of thefacial nerve and placement of a sponge between the fa-cial nerve and impinging vascular structures has beensuccessful in many cases, but the surgical risks of suboc-cipital craniotomy (including stroke and deafness) mustbe considered.21,23

Facial Myokymia

Unlike the intermittent spasms of hemifacial spasm,facial myokymia is a continuous, unilateral, undulatingmovement that often appears to ripple across the face.This disorder may be isolated to the orbicularis oculimuscles initially, but over time involves all of the unilat-eral facial muscles, and is occasionally bilateral.24 In ad-vanced cases, the myokymia progresses to a continuoustonic facial contracture, associated with facial paralysis.This is called spastic-paretic facial contracture.

Facial myokymia is generally caused by lesions im-mediately rostral to or involving the facial nucleus andits fascicles within the pons. Common causes includemultiple sclerosis in adults, and pontine glioma in chil-dren or young adults. Facial myokymia has also been as-sociated with extra-medullary brain stem compression,brain stem infarction and infection, Guillain–Barré syn-


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Figure 7. Pseudoptosis from dermatochalasis. (A) This62-year-old man appears to have narrowed ocular fis-sures. However, this appearance is the result of looseskin from the upper eyelids prolapsing over the eyelidmargin. (B) When the skin of the upper eyelids is gentlyretracted, the normal position of the upper eyelid margincan be appreciated.

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drome, toxins, anoxia, and obstructive hydrocephalus.Neuroimaging is absolutely required in all patients withfacial myokymia. In most cases, the underlying causecannot be definitively removed. Carbamazepine (Tegre-tol®), baclofen, or clonazepam may offer limited symp-tomatic relief.5,24

Benign Orbicularis Myokymia

Benign orbicularis myokymia is a common com-plaint in otherwise normal individuals, consisting of anirritating unilateral twitching movement of the lower (orless often, upper) eyelids. The twitching is rapid andepisodic, lasting hours or even days at a time, and doesnot involve any other portions of the face. Associatedfactors include stress, fatigue, as well as caffeine andnicotine intake. This benign disorder can be distin-guished from hemifacial spasm and blepharospasm bythe lack of involvement of any other portion of the faceor opposite eye, and the absence of any other neurologi-cal or neuro-ophthalmic findings (Fig. 8).

Following Facial Nerve Palsy

Aberrant regeneration of the facial nerve frequentlyoccurs following facial nerve injury. Facial nerve fibersthat originally were directed to the lower face may bemisdirected to the orbicularis, resulting in a narrowingof the fissure with movements of the lips or mouth(Table 4).

Generalized increased facial tone commonly occursfollowing recovery from Bell’s palsy, resulting in a nar-rowing of the ocular fissure on the affected side.

EYELID RETRACTION

Eyelid retraction refers to an abnormally high posi-tion of the upper lid, giving the appearance of “staring.”

Retraction of the lower lid may also contribute to thisappearance. Lid retraction may give the false impressionof exophthalmos, and patients may present with a com-plaint that their “eye has gotten bigger.” Causes of eyelidretraction are outlined in Table 5, and described in moredetail below.

Orbital Graves’ Disease

Orbital Graves’ disease is an autoimmune disordercharacterized by enlargement of the extra-ocular mus-cles and an increase in orbital fat volume, causing prop-tosis, diplopia, and ocular congestion (Fig. 9). Eyelid re-traction is a conspicuous sign, and occurs independentlyof the proptosis by an unknown mechanism.

Eyelid retraction can occur from other disorders,25

but is often specific for Graves’ disease when accompa-nied by proptosis and restrictive orbitopathy. Not un-commonly, lid retraction may be the first and only visi-ble sign of orbital Graves’ disease. Lid lag, or failure ofthe eyelid to follow with the globe in down-gaze, is usu-ally present with lid retraction.

The combination of proptosis, lid retraction, and lidlag can produce an exposure keratopathy, causingblurred vision and pain. The severity of ocular surfacedisease dictates the intensity of treatment, and may in-clude artificial tears, ointment, moisture shields, taping


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Figure 8. Facial involvement in hy-peractivity states. Regions of the facecommonly involved in facial hyperac-tivity states are shown. (Courtesy ofMartin TJ, Corbett JJ. Requisites inNeuro-ophthalmology, St. Louis:Mosby; 2000, Figure 12.7.)

Table 5. Differential Diagnosis of Eyelid Retraction

Graves’ disease (unilateral or bilateral)Midbrain disorders (bilateral, but may be asymmetric)Aberrant regeneration of the oculomotor nervePseudo-retraction

from contralateral ptosisfrom ipsilateral facial palsy (acute)

Levator restriction from trauma or surgery

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the eye closed at night, tarsorrhaphy, or levator recessionsurgery.

About 5% of patients with Graves’ disease alsohave myasthenia gravis. The coexistence of multiple au-toimmune disorders is not uncommon, and suggests anunderlying fundamental immune derangement. There-fore, patients with orbital Graves’ disease can actuallypresent with ptosis, rather than lid retraction.

The orbit and thyroid gland are end-organs affectedby a poorly understood underlying systemic autoim-mune disorder. Therefore, thyroid dysfunction is not in-variably present with Graves’ orbitopathy and normalthyroid function does not rule out this entity.

Supranuclear Disorders

Lesions involving the dorsal midbrain can causesymmetric bilateral eyelid retraction (called Collier’ssign), as part of a constellation of signs called dorsalmidbrain syndrome or Parinaud’s syndrome. Other com-monly associated findings include convergence-retraction nystagmus, pupillary light-near dissociation,vertical gaze dysfunction, and convergence abnormali-ties.5 This form of lid retraction can be distinguishedfrom the lid retraction in Graves’ disease, as the eyelidsfollow the globe normally in down-gaze (no lid lag). If adorsal midbrain lesion also affects the oculomotor fasci-cles on one side, the patient can present with lid retrac-tion on one side, and ptosis on the other (called “plus–minus” syndrome).26

Aberrant Regeneration of the Oculomotor Nerve

Aberrant regeneration of the third cranial nerve of-ten involves the eyelid. Not uncommonly, eyelid retrac-tion will occur with attempted adduction and/or depres-sion of the globe, as fibers originally innervating themedial or inferior rectus now innervate the levator mus-cle. This important finding will be missed unless the ex-aminer specifically looks for eyelid elevation in the infe-

rior positions of gaze (without holding the eyelids).Other synkinetic syndromes are discussed in Table 4.

Mechanical

Mechanical factors that restrict the normal compli-ance of the levator palpebrae or other eyelid componentstypically cause lid lag, but may cause lid retraction whensevere. Examples include metastatic schirrous carci-noma of the breast and scarring from lacerations, burns,or orbital infections.

Pseudo-retraction from Contralateral Ptosis

The levator palpebrae muscles in the right and lefteyes are yoked muscles, operating with equal innervationaccording to Hering’s law. The extra effort generated tolift a partially ptotic lid on one side can give the appear-ance of eyelid retraction on the opposite side. Thispseudo-retraction will disappear when the ptotic eyelidis manually elevated.

ORBICULARIS WEAKNESS

Unilateral orbicularis weakness may cause anasymmetry of the ocular fissures in primary position atrest, but is usually manifest clinically as an incompleteblink or poor eye closure.

Facial Nerve Palsies

BELL’S PALSY. Bell’s palsy is the most commonfacial neuropathy. This condition has always been de-scribed as an idiopathic facial paralysis in the past, but recent evidence suggests a viral (herpes simplex)etiology.27–29

Facial weakness in Bell’s palsy generally developsquite rapidly. Pain (usually retroauricular) is common


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Figure 9. Eyelid retraction in Gravesdisease. This 45-year-old woman withorbital Graves disease has bilateral lidretraction and proptosis.

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and may antedate the onset of paralysis by hours or days.Additional signs and symptoms include facial numb-ness, numbness of the tongue, decreased tearing, alteredtaste, and dysacousis. Obicularis weakness is often pro-found, and the resultant exposure keratopathy can haveserious consequences.

Greater than 80% of patients have a “satisfactory”recovery. Improvement usually begins within 3 weeks ofonset. By 3 to 4 months, the degree of recovery is usu-ally complete, and improvement is not expected beyondthis point. The treatment recommendations for Bell’spalsy continue to evolve, and currently include the useof antiviral agents.14

OTHER CAUSES OF FACIAL NERVE PALSY. In-fectious diseases that can cause facial nerve palsy in-clude Herpes Zoster oticus, Lyme disease, human immu-nodeficiency virus (HIV). Guillian–Barré syndrome(acute inflammatory demyelinating polyradiculopathy,or AIDP), sarcoidosis, head trauma, and tumors (cere-bellopontine angle tumors, parotid tumors) commonlyinvolve the facial nerve.27

Möbius’ syndrome is a congenital disorder ofnuclear agenesis that consists of bilateral facial pal-sies, gaze palsies, and multiple other potential cranialneuropathies.

As in Bell’s palsy, treatment of the potentially dev-astating complications of orbicularis weakness—expo-sure keratopathy and its sequelle—must be addressed.

Myopathic Diseases and Myasthenia Gravis

Disorders that cause myopathic facial weakness(such as myotonic dystrophy, CPEO, or other musculardystrophies) and myasthenia gravis can also cause weak-ness of eyelid closure. Interestingly, most of these samedisorders are characterized by ptosis from weakness ofeyelid retractors. Orbicularis weakness may only be evi-dent when the patient is asked to tightly close their eyes.Patients with myasthenia may be able to initiate tightclosure of the eyelids, but with fatigue weakness of theorbicularis muscle becomes evident (the so-called “peeksign”).30

EXPOSURE KERATOPATHY FROMORBICULARIS WEAKNESS

Preventing the potentially serious sequelae of expo-sure keratopathy is vital in caring for patients with pooreye closure. Exposure keratopathy leads to epithelialbreakdown with corneal erosion, and the potential forcorneal ulceration, corneal perforation, or endoph-thalmitis.

The degree of orbicularis weakness is the primarydeterminant of corneal exposure risk. Another importantfactor is the presence and effectiveness of the Bell’s phe-nomenon. This reflexive upper rotation of the eyes oneye closure may protect the cornea even when the eyecannot be completely closed. The presence of relativecorneal anesthesia adds considerable risk for the devel-opment of keratopathy in the setting of orbicularisweakness. Specifically evaluating these three factors:

the degree of orbicularis weakness, the Bell’s phenome-non, and corneal sensation, along with the anticipated re-covery time, determine how aggressive the treatmentmust be to protect the eye. All patients at risk for expo-sure keratopathy should be started on topical artificialtears at regular intervals throughout the day and oint-ment at night. Prompt referral to an ophthalmologist isrequired in most cases, especially those patients withprofound orbicularis weakness or those with an antici-pated chronic course. Tarsorrhaphy, injection of the lev-ator palpebrae muscle with botulinum toxin, placementof gold weights in the upper eyelid, or other therapiesmay be necessary.

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Documents

Abnormalities of Eyelid Position and Function · (Fig. 1). The levator palpebrae superiorus muscle is the primary retractor (raises the eyelid and opens the eye) of the upper eyelid