Residency · Residency · Ophthalmology

Eyelid Malpositions: Ptosis, Entropion, and Ectropion

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Alright, intern, look alive. I know you're tired, but eyelids are more than just flaps of skin. Imagine Mrs. Henderson, a sweet 80-year-old, coming in with her lower lid rolled inward. Her lashes are constantly scraping her cornea, making her tear up and feel like there's sand in her eye. That's entropion. Her problem? Her eyelid has gotten a bit too loose horizontally, the little muscles that pull it down have detached, and another muscle is overacting, pushing everything inwards. For her, we'd likely do a lateral tarsal strip to tighten things up, reattach those retractors, and reposition that overactive muscle. If we don't fix it, she's looking at corneal abrasions, maybe even an ulcer.

Now picture Mr. Johnson, a contractor, whose lower lid rolls outward. He's constantly wiping away tears, his eye looks red, and the white part, the conjunctiva, is starting to look thick and leathery. That's ectropion. His lid is just too loose, probably from years of sun exposure and gravity. For him, a similar procedure, a lateral tarsal strip, would tighten that lid right up, bringing it back into place. And then there's young Sarah, a kindergartner, whose upper eyelid droops so much it's covering her pupil. That's ptosis. If we don't fix that, her brain might just ignore the blurry image from that eye, leading to permanent vision loss, or amblyopia. We'd assess how well her eyelid lifting muscle, the levator, works. If it’s strong enough, we might just tighten that muscle or reattach it; if it’s really weak, we might need to use her forehead muscle to lift the lid with a sling. Each of these patients needs a specific fix because the underlying problem, even if it looks similar on the surface, is unique.

Introduction

Eyelid malpositions are among the most common conditions encountered in oculoplastic practice. Ptosis, entropion, and ectropion each result from distinct anatomic and pathophysiologic mechanisms, and accurate diagnosis is essential for selecting the appropriate surgical correction. This lecture reviews the classification, evaluation, and surgical management of these three entities.

Ptosis

Definition and Classification

Ptosis (blepharoptosis) is an abnormally low upper eyelid position. Normal margin-reflex distance 1 (MRD1) is 4-5 mm. Classification by etiology:

Aponeurotic -- most common; involutional dehiscence or disinsertion of the levator aponeurosis. Myogenic -- myasthenia gravis, chronic progressive external ophthalmoplegia, myotonic dystrophy. Neurogenic -- cranial nerve III palsy, Horner syndrome. Mechanical -- lid mass, dermatochalasis, cicatricial changes. Traumatic -- post-surgical or post-injury levator damage.

Clinical Evaluation

Measure MRD1, MRD2, palpebral fissure height, and levator function (normal >= 12 mm) Assess phenylephrine test for Muller muscle-conjunctival resection (MMCR) candidacy. Rule out pseudoptosis: dermatochalasis, contralateral lid retraction, hypotropia, enophthalmos. Check for Hering dependence by elevating the ptotic lid and observing the contralateral lid.

Surgical Options

Levator advancement/resection -- levator function >= 5 mm. Muller muscle-conjunctival resection (MMCR) -- mild ptosis with positive phenylephrine test. Frontalis sling -- levator function < 4 mm (e.g., congenital ptosis, CN III palsy)

Entropion

Definition and Classification

Entropion is inward turning of the eyelid margin, causing lash-cornea contact and irritation.

Involutional -- most common; horizontal lid laxity, lower retractor disinsertion, overriding preseptal orbicularis. Cicatricial -- tarsal conjunctival scarring (trachoma, Stevens-Johnson syndrome, ocular cicatricial pemphigoid, chemical burns) Congenital -- rare; epiblepharon is more common in Asian children. Spastic -- acute orbicularis spasm secondary to ocular irritation.

Surgical Management

Involutional: quickert sutures (temporary), lateral tarsal strip + lower retractor reinsertion + orbicularis repositioning. Cicatricial: posterior lamellar graft (mucous membrane, hard palate, amniotic membrane)

Ectropion

Definition and Classification

Ectropion is outward turning of the eyelid margin, leading to exposure, tearing, and conjunctival keratinization.

Involutional -- horizontal lid laxity, canthal tendon laxity. Cicatricial -- skin shortage from trauma, burns, prior surgery, actinic damage. Paralytic -- facial nerve (CN VII) palsy. Mechanical -- lid tumor, edema, orbital fat prolapse.

Surgical Management

Involutional: lateral tarsal strip procedure, medial canthal tendon plication if medial ectropion present. Cicatricial: skin graft (full-thickness from upper lid or postauricular) or flap reconstruction. Paralytic: gold weight implant, lateral tarsorrhaphy, canthoplasty.

Complications of Untreated Eyelid Malpositions

Corneal abrasion, ulceration, and scarring (entropion) Chronic epiphora and conjunctival keratinization (ectropion) Exposure keratopathy and secondary infection. Amblyopia in pediatric congenital ptosis with visual axis occlusion.

Key Clinical Pearls

Always check for Hering dependence before ptosis surgery to avoid unmasking contralateral ptosis. A positive phenylephrine test (>= 2 mm lid elevation) predicts good MMCR outcomes. Involutional entropion has three pathogenic components; address all three for durable repair. Cicatricial ectropion requires tissue replacement, not simply horizontal tightening. In paralytic ectropion, prioritize corneal protection while awaiting potential nerve recovery.

References

1. Finsterer J. Ptosis: causes, presentation, and management. Aesthetic Plast Surg. 2003;27(3):193-204.
2. Vallabhanath P, Carter SR. Ectropion and entropion. Curr Opin Ophthalmol. 2000;11(5):345-351.
3. Nerad JA. Oculoplastic Surgery: The Requisites in Ophthalmology. Mosby; 2001.
4. American Academy of Ophthalmology. Orbit, Eyelids, and Lacrimal System. BCSC Section 7. 2023-2024.

For the intern

At 3am, your priority is corneal protection. For entropion, temporarily evert the lid with tape or a Quickert suture to prevent further corneal abrasion. For ectropion or severe ptosis causing exposure, apply lubricating ointment and consider temporary taping or a moisture chamber. Check visual acuity and perform fluorescein staining to rule out corneal ulceration requiring urgent ophthalmology consultation. Definitive surgical repair can wait for morning or outpatient clinic unless there's active corneal infection. For acute facial nerve palsy with lagophthalmos, initiate aggressive lubrication immediately—corneal exposure keratopathy can develop within hours.

Common pitfalls

• Missing Hering dependence: Failing to manually elevate the ptotic lid during examination means you won't detect contralateral pseudoptosis that will unmask after unilateral repair, leading to unhappy patients requesting second-eye surgery.

• Taping entropion incorrectly: Taping the lid downward worsens entropion. Instead, pull the lower lid skin-muscle layer inferiorly and laterally to evert the margin away from the cornea before securing with tape to the cheek.

• Assuming all ptosis needs surgery urgently: Most ptosis is chronic and elective. The exception is acute ptosis with diplopia or pupil involvement—think third nerve palsy or myasthenia crisis and consult neurology emergently.

• Overlooking the phenylephrine test: This simple office test predicts who benefits from the less-invasive Muller muscle-conjunctival resection versus formal levator surgery, preventing unnecessary extensive procedures.

Make it stick

Imagine you're on call, and a patient with a history of stroke presents with new-onset left eyelid droop, double vision, and a dilated left pupil. Your initial thought races to ptosis. You carefully examine the patient, noting the constricted left pupil and anhydrosis on the left side of their face. This classic triad, though subtle at first, immediately points you away from a simple benign ptosis. This patient likely has a third cranial nerve palsy with pupil involvement, a neurosurgical emergency until proven otherwise. This scenario highlights how seemingly straightforward eyelid issues can be red flags for critical systemic conditions, underscoring the importance of a thorough, systematic approach to diagnosis.

If you remember one thing

Always consider the patient’s systemic health and neurological status when evaluating eyelid malpositions, as they can be the first sign of life-threatening conditions. Prioritize corneal protection in all acute eyelid malpositions to prevent irreversible vision loss.

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