Eyelid abnormalities and facial movement disorders are frequently encountered in ophthalmology. Many such problems are neurologic in origin and therefore require careful evaluation. A thorough history of the presenting complaints is essential, as is documentation of concomitant medical conditions. Although most patients are aware of an abnormality in the position or function of the eyelid, some may present instead with a chief concern of visual difficulties (eg, visual loss from ptosis) or pain (eg, exposure keratopathy from facial palsy). Occasionally, patients will attribute the problem to the wrong eye, for example mistaking ptosis for contralateral eyelid retraction, or widening of the palpebral fissure for contralateral ptosis. The clinician should ask about onset and duration of symptoms, as well as associated symptoms. In addition, the clinician should perform a careful evaluation of eyelid function and facial movements along with a thorough ophthalmic examination. Diagnosis and management of eyelid disorders are discussed at greater length in BCSC Section 7, Oculofacial Plastic and Orbital Surgery.
An examination of the eyelids begins by observing their general shape and appearance (eg, an S shape may indicate pathology affecting the lacrimal gland or neurofibromatosis [Fig 11-1; see also Chapter 14]) and blink rate (eg, low in Parkinson disease and high in blepharospasm), and by noting abnormal movements (eg, synkinesis with other facial muscles). If the ptosis is unilateral, the clinician should verify that it is not an artifact of vertical strabismus (eg, hypotropia; Fig 11-2) or contralateral eyelid retraction. The eyelids should be everted for examination to rule out a local cause of ptosis, such as retained contact lens or giant papillary conjunctivitis. If the ptosis is asymmetric, the clinician should manually raise the ptotic eyelid to see if the higher eyelid drops to a new position (Fig 11-3).
Figure 11-1 Ptosis in a 2-year-old with neurofibromatosis; the S-shaped eyelid margin results from the presence of a plexiform neurofibroma.
(Courtesy of Steven A. Newman, MD.)
When evaluating a patient with ptosis, the clinician should obtain the following 5 important clinical measurements:
levator palpebrae superioris muscle function
vertical palpebral fissure height
upper eyelid crease position
lagophthalmos amount (if present)
Figure 11-2 Pseudoptosis. A, Patient with pseudoptosis from a large left hypotropia. B, Occlusion of the right eye revealed markedly improved upper eyelid position.
(Courtesy of M. Tariq Bhatti, MD.)
Figure 11-3 Myasthenia gravis. A, Patient with myasthenia gravis and ptosis that is greater on the left side than on the right. B, Manual opening of the left eyelid results in greater right-sided ptosis (enhanced ptosis). This sign, although often present with myasthenia gravis, is not specific. It may occur with other disorders producing asymmetric ptosis and is a manifestation of Hering’s law of equal innervation.
(Courtesy of Rod Foroozan, MD.)
Descriptions of these measurements are provided in Chapter 12 of BCSC Section 7, Oculofacial Plastic and Orbital Surgery.
In addition, eyelid movement during target pursuit from upgaze to downgaze should be observed. Normally, such movement is smoothly accomplished, but lid lag may occur in patients with thyroid eye disease or as a result of aberrant regeneration of cranial nerve (CN) III (see Chapter 7, Fig 7-10).
To aid diagnoses of cases of suspected fatigable ptosis caused by myasthenia gravis, the patient can be asked to fixate on the clinician’s hand, which is elevated to provoke extreme upgaze. The clinician watches for progressive ptosis as the patient attempts to hold this position. A patient without myasthenia gravis can maintain the position without developing ptosis. The Cogan lid-twitch sign, a feature of myasthenia gravis, can be identified by having the patient fixate in downgaze for a few seconds and then rapidly refixate straight ahead. The sign appears as an upward overshoot of the eyelid followed by fluttering as the eyelid settles into position (videos of lid twitch and lid twitch sign are available at The Neuro-Ophthalmology Virtual Education Library [NOVEL] website at http://novel.utah.edu).
Evaluation of facial motor function includes assessing the strength of the orbicularis oculi and other facial muscles. Eyelid closure should be assessed to determine if it is incomplete (lagophthalmos). Reinnervation phenomena, such as synkinesis with eyelid closure and facial tics, may be signs of a previous injury to CN VII (Fig 11-4). The clinician should note the presence of exophthalmos (eg, thyroid eye disease) or enophthalmos. Enophthalmos may result in apparent ptosis and narrowing of the palpebral fissure because the eyelid follows the contour of the globe as the eye retracts into the orbit. Anisocoria (see Chapter 10) may suggest sympathetic nervous system disruption, which will alter eyelid position. Dysfunction of CN III with parasympathetic nervous system involvement may also present with ptosis and anisocoria, as well as an ocular motility deficit. Finally, “neighboring” CNs should be assessed. If ptosis is caused by CN III weakness, the functions of CN IV, CN V, and CN VI should also be evaluated. Ocular motility should be checked for subtle weakness. Similarly, if CN VII dysfunction is found, facial sensation and hearing should be evaluated.
Figure 11-4 Facial nerve synkinesis. Misdirection may occur with recovery of CN VII function. A, In this 54-year-old patient, aberrant regeneration of left CN VII after resection of a cerebellopontine angle meningioma caused eyelid closure when she attempted to smile (B).
(Courtesy of Steven A. Newman, MD.)
Excerpted from BCSC 2020-2021 series: Section 5 - Neuro-Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.