Blepharoptosis (ptosis) is abnormal drooping of the upper eyelid with margin reflex distance 1 (MRD1) measured from corneal light reflex to upper lid margin <2.5 mm (normal 4-5 mm) or asymmetry >1 mm between eyes. Causes visual field obstruction (especially superior), asthenopia, brow ache from compensatory frontalis activation, head tilt (chin-up), and cosmetic concern. Affects 5-10% of population (most age-related), with bilateral or unilateral presentation.
Classification by etiology and timing: Congenital ptosis (present at birth, due to levator palpebrae superioris muscle dystrophy with fatty infiltration, often unilateral, associated with absent upper lid crease, lid lag in downgaze, monocular elevation deficiency in 5%, blepharophimosis-ptosis-epicanthus inversus syndrome BPES with autosomal dominant inheritance). Acquired aponeurotic ptosis (involutional, most common in adults, due to dehiscence/disinsertion of levator aponeurosis from tarsus with age, contact lens use, prior eye surgery, repeated rubbing). Neurogenic ptosis (third nerve palsy with pupil involvement is a neurosurgical emergency, posterior communicating artery aneurysm; Horner syndrome with miosis and anhidrosis; myasthenia gravis with fatigability). Myogenic ptosis (myasthenia gravis, chronic progressive external ophthalmoplegia CPEO, oculopharyngeal muscular dystrophy OPMD, myotonic dystrophy, mitochondrial disease). Mechanical ptosis (eyelid masses: chalazion, neoplasm, hemangioma; severe edema; scarring from trauma, burns). Traumatic ptosis (direct levator injury, hematoma, neurogenic from skull base injury). Pseudoptosis (apparent ptosis from contralateral lid retraction, hypotropia, anophthalmos, microphthalmia).
Evaluation: history (onset, duration, fluctuation, fatigability, family history, contact lens, surgery, neurological symptoms, dysphagia, weakness), examination including MRD1 (corneal reflex to upper lid), MRD2 (corneal reflex to lower lid), levator function (lid excursion from downgaze to upgaze, normal >12 mm, fair 5-11 mm, poor <5 mm), upper lid crease position (high in aponeurotic, absent in congenital), tarsal platform show, brow position (frontalis compensation), eye movements (diplopia, ophthalmoplegia), pupil examination (third nerve, Horner), Bell phenomenon, ice test (improvement >2 mm with ice pack on closed lid for 2 minutes is sensitive for myasthenia), edrophonium test, fatigability (sustained upgaze 60 seconds), Hering's law contralateral lid retraction, phenylephrine 2.5% test (predicts response to Müller muscle surgery if 2 mm elevation). Workup: acetylcholine receptor antibodies and MUSK antibodies for myasthenia, MRI/MRA for third nerve palsy, CT of orbit for tumors, mitochondrial workup if CPEO. Treatment: observation in mild without functional/cosmetic impact, ptosis crutches mounted on glasses for non-surgical candidates, treat underlying disease (myasthenia: pyridostigmine, immunotherapy; thyroid eye disease: euthyroid optimization). Surgical correction depends on levator function: External levator advancement/resection (good function >10 mm, most common adult procedure), Müller muscle-conjunctival resection (Putterman, good function with positive phenylephrine response), frontalis sling (poor levator function <4-5 mm, congenital severe ptosis, third nerve palsy, using autologous fascia lata, silicone, or ePTFE), Whitnall sling, Fasanella-Servat (mild ptosis with good function). Outcomes: 80-90% successful, complications include undercorrection (most common, 10-15%), overcorrection, lagophthalmos with corneal exposure, contour abnormalities, asymmetry, recurrence.