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crease and eyelid fold, loss of eyelashes, conjunctival prolapse, and upper eyelid ectropion also may complicate surgery. In addition, retrobulbar hemorrhage is a risk with all eyelid surgery, and, although rare, infection is a potential complication.

Schaefer AJ, Schaefer DP: Classification and correction of ptosis. In Stewart WB (ed): Surgery of the Eyelid, Orbit, and Lacrimal System, vol. 2. San Francisco, American Academy of Ophthalmology, 1994,

pp 128–131.

17.What is Marcus Gunn’s jaw-winking syndrome?

Marcus Gunn’s syndrome is a unilateral congenital ptosis with synkinetic innervation of the levator and ipsilateral pterygoid muscle. Patients demonstrate retraction of the ptotic eyelid on stimulation of the ipsilateral pterygoid muscles by either opening the mouth or moving the jaw to the opposite side.

18.Describe the anatomy of Whitnall’s ligament and its significance in ptosis.

Whitnall’s ligament, also known as the superior transverse ligament, is a condensation of collagen and elastic fibers on the anterior levator sheath as it changes from muscle to aponeurosis. It attaches medially near the trochlea and laterally traverses through the lacrimal gland, attaching to the lateral orbital wall approximately 10 mm above the lateral orbital tubercle. It serves as a suspensory ligament for the upper eyelid and is the point where the vector forces of the levator muscle transfer from an anterior-posterior direction to a superior-inferior direction. It is an important landmark for performing large levator resections.

Kersten RC: Orbit, Eyelids, and Lacrimal System: Basic and Clinical Science Course. San Francisco, American Academy of Ophthalmology, 2006.

19.What is the concern when Horner’s syndrome presents with pain?

Patients with neck pain, facial pain, or headache and acute Horner’s syndrome should be suspected of having a carotid artery dissection. Work-up should be urgent and include magnetic resonance imaging or angiography and carotid Doppler ultrasound of the neck. A carotid dissection usually requires urgent anticoagulation and neurovascular consultation.

Chan C, Paine M, O’Day J: Carotid dissection: A common cause of Horner’s syndrome. Clin Exper Ophthalmol 29:411–415, 2001.

KEY POINTS: FEATURES OF HORNER’S SYNDROME

1.Mild ptosis (1–2 mm)

2.Miosis

3.Anhydrosis

4.Reverse ptosis of the lower eyelid

5.Hypopigmentation of iris (congenital cases)

20.Name some useful tests for diagnosing myasthenia gravis.

&Ice test (in office)

&Acetylcholine receptor antibody blood test: False-negative results in 50% of cases

&Edrophonium chloride (Tensilon) test

&Single-fiber electromyography (orbicularis muscle)

Kerrison JB, Newman NJ: Five things oculoplastic surgeons should know about neuro-ophthalmology. Ophthal Plast Reconstr Surg 15:372–377, 2002.

1.What clues are helpful in determining whether an eyelid lesion is benign or malignant?

The size, location, age of onset, rate of growth, presence of bleeding or ulceration, any color change, history of malignancy, or prior radiation therapy are important. A thorough examination is necessary. Malignant or inflammatory lesions may cause loss of eyelashes and distortion of meibomian gland orifices, but only malignant lesions destroy the orifices. If a lesion is near the lacrimal punctum, evaluate for

invasion to the lacrimal system. Probing and irrigation may be necessary. Palpate lesions for fixation to deep tissues or bone. Regional lymph nodes also should be examined for enlargement. Restriction of extraocular motility and proptosis are clues to localized invasion. If a sebaceous adenocarcinoma or melanoma is diagnosed, system evaluation should target lung, liver, bones, and neurologic systems. Any lesion to be treated or

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316 EYELID TUMORS

3.What eyelid lesion is associated with a chronic follicular conjunctivitis?

Molluscum contagiosum. A virus causes the multiple waxy nodules with umbilicated centers. They may resolve spontaneously but frequently require surgical excision or cautery to prevent reinfection.

4.What blood tests should you

order in young patients with the lesions shown in Fig 38-3?

The appropriate tests are cholesterol level, triglyceride level, and fasting blood sugar. Xanthelasma are yellowish plaques found at the medial canthal area of the upper and lower eyelids. They are collections of lipid. In older patients, xanthelasma are common and no cause for concern. In younger patients they may be a sign of hypercholesterolemia, a congenital disorder of cholesterol metabolism, or diabetes mellitus. They may be removed for cosmetic purposes, but they may recur.

5.What is a keratoacanthoma? What malignancy does it simulate?

A keratoacanthoma is a rapidly growing lesion that appears over several weeks. It is hyperkeratotic with a central crater that often resolves spontaneously

(Fig. 38-4). Clinically, the lesion

simulates a ‘‘rodent ulcer’’ basal cell carcinoma. Microscopically, the lesion appears similar to squamous cell carcinoma. It may occur near the edge of areas of chronic inflammation, such as a burn, or on the periphery of a true malignant neoplasm. If you are sure of the diagnosis, it is reasonable to observe. However, because it may cause destruction of the eyelid margin, lesions in this area are often removed surgically. In addition, steroids may be injected into the lesion to hasten resolution.

6.What is the most common malignant eyelid tumor?

Basal cell carcinoma, which is most common in middle-aged or elderly patients.

7.What are its two clinical presentations?

Nodular (Fig. 38-5) and morpheaform (Fig. 38-6) tumors. A nodular tumor is a firm, raised, pearly, discrete mass, often with telangiectasias over the tumor margins. If the center of

the lesion is ulcerated, it is called a rodent ulcer. Morpheaform tumors are firm, flat lesions with indistinct borders. They tend to be more aggressive and have a worse prognosis than the nodular variety.