Ptosis (Drooping Eyelid): Causes, Diagnosis, and Surgical Correction — Overview, Diagnosis & Treatment Options | MyMedicPlus

Ptosis (blepharoptosis) is an abnormally low position of the upper eyelid margin, defined as the margin-reflex distance (MRD1) being less than 2 mm (normal MRD1 is 4–5 mm). It ranges from mild cosmetic drooping to severe obstruction of the visual axis causing deprivation amblyopia in children. Ptosis may be unilateral or bilateral and is classified by etiology into congenital or acquired, and by mechanism — aponeurotic (most common in adults), myogenic, neurogenic, mechanical, or traumatic. Involutional (aponeurotic) ptosis is the most prevalent type in adults, resulting from age-related levator aponeurosis dehiscence or disinsertion, and accounts for approximately 70% of adult ptosis cases. The condition significantly impairs quality of life — causing visual field deficits, brow ache from compensatory frontalis overaction, head tilt, and cosmetic concerns. In children, unilateral or severe bilateral ptosis must be treated promptly to prevent amblyopia ('lazy eye') from visual axis obstruction during the critical period of visual development.

Ptosis has multiple etiological categories. Aponeurotic (involutional) ptosis results from dehiscence or disinsertion of the levator aponeurosis from the tarsal plate — the most common cause in adults, associated with aging, contact lens wear, eye rubbing, and prior ocular surgery. Congenital ptosis arises from dysgenesis or maldevelopment of the levator muscle itself, causing poor or absent levator function; it may be isolated or associated with superior rectus weakness. Neurogenic ptosis results from third cranial nerve palsy (oculomotor nerve — accompanied by dilated pupil, restricted eye movement, and exotropia, which may indicate a compressive lesion such as posterior communicating artery aneurysm), Horner syndrome (ptosis, miosis, anhidrosis from sympathetic pathway interruption), or Marcus Gunn jaw-winking ptosis (aberrant innervation between trigeminal and levator palpebrae). Myogenic ptosis occurs in myasthenia gravis (variable, fatigable ptosis improving with edrophonium/ice pack test), chronic progressive external ophthalmoplegia (CPEO), and myotonic dystrophy. Mechanical ptosis results from excess eyelid weight (chalazion, tumor, amyloid). Traumatic ptosis follows lid laceration or hematoma.

The defining symptom is a visibly drooping upper eyelid on one or both sides. In mild ptosis, patients may notice asymmetry in eyelid height, particularly in photographs. Moderate-to-severe ptosis causes progressive visual field obstruction — particularly the superior visual field — leading to difficulty reading, driving, and descending stairs. Compensatory frontalis muscle overaction — raising the eyebrows to elevate the lids — causes chronic forehead and brow ache. Chin-up head tilt develops as patients position their head to look under the drooping lid. In children, unilateral severe ptosis may cause amblyopia (reduced vision in the affected eye due to deprivation during visual development) manifesting as reduced visual acuity, absent stereopsis, or strabismus. Neurogenic ptosis from third nerve palsy presents with associated diplopia, large unreactive pupil, and downward/outward eye deviation — a neurological emergency if of sudden onset. Myasthenic ptosis is characteristically variable and fatigable — worsening with sustained upgaze and improving after rest or with ice application to the lid.

Clinical assessment begins with documentation of the degree of ptosis using standard measurements: MRD1 (margin to corneal reflex distance), levator function (LF — excursion of the upper lid between downgaze and upgaze, normal ≥12 mm), upper lid crease height, and Bell's phenomenon (adequacy of corneal protection with eye closure). Levator function is the most important measurement guiding surgical technique selection. External photography and visual field testing (Humphrey or Goldmann) with and without lid elevation document functional impact. Slit-lamp examination assesses corneal integrity and tear film. Pupil examination is critical — a dilated, unreactive pupil accompanying ptosis mandates emergency evaluation for posterior communicating artery aneurysm (MRI/MRA or CT angiography). Ice pack test confirms myasthenia gravis (improvement in ptosis after 2 minutes of ice application). Anti-AChR antibodies, anti-MuSK antibodies, and single-fiber EMG confirm myasthenia gravis. Tension (edrophonium) test is performed in selected cases. CT or MRI brain and orbit is indicated when neurogenic or mechanical causes are suspected. Thyroid function tests are performed when thyroid eye disease is considered.

Treatment depends on the etiology, severity, and levator function. For myasthenia gravis, treatment of the underlying condition with pyridostigmine, immunosuppressants (prednisolone, azathioprine), or thymectomy usually improves ptosis. Third nerve palsy ptosis may resolve spontaneously if ischemic; surgical correction is deferred until spontaneous recovery has plateaued (typically 6–12 months). Surgical ptosis repair (blepharoptosis correction) is indicated for functional visual obstruction or amblyopia risk. Levator aponeurosis advancement/repair is the procedure of choice for aponeurotic ptosis with good levator function (LF ≥5 mm) — the aponeurosis is reattached to the tarsal plate through an upper lid crease incision under local anesthesia, allowing intraoperative adjustment to optimal lid height. Levator resection (external approach) or Fasanella-Servat procedure (tarso-conjunctival Mullerectomy) are used for moderate levator function (LF 4–8 mm). Frontalis suspension — using a sling of silicone rod, Gore-Tex, or autologous fascia lata — is performed for poor levator function (LF <4 mm), as in congenital ptosis with absent levator function. Pediatric ptosis causing visual axis obstruction requires surgery before age 3 to prevent amblyopia, combined with amblyopia occlusion therapy.

The prognosis following ptosis treatment is generally excellent when the underlying etiology is correctly identified and the appropriate surgical technique is selected. Levator aponeurosis advancement for aponeurotic (involutional) ptosis — the most common adult form — achieves acceptable lid height and symmetry in 85–95% of cases, with good functional and cosmetic outcomes that are maintained over the long term. Frontalis suspension for congenital ptosis with absent levator function produces reliable functional results, allowing lid elevation with brow movement; undercorrection or overcorrection requiring revision occurs in approximately 10–20% of cases. In children with amblyopia-causing congenital ptosis, early surgical intervention combined with occlusion therapy achieves excellent visual outcomes — amblyopia is fully or partially reversible when treated within the sensitive period of visual development (before approximately age 7–8 years). Prompt surgery in ptosis obstructing the visual axis prevents permanent visual deficit. Myasthenia gravis-related ptosis typically improves substantially with medical treatment of the underlying condition, and surgical correction is reserved for stable residual cases. Ischemic third nerve palsy causing acute-onset ptosis usually resolves spontaneously within 6–12 weeks, with surgery deferred until recovery has plateaued. Compressive third nerve palsy may recover after decompression, though the timeline varies. Ptosis surgery carries a known rate of under- and overcorrection of approximately 10–15%, necessitating adjustment or reoperation in some patients. Long-term ophthalmic surveillance is recommended after surgery to monitor for lagophthalmos, exposure keratopathy, lid height changes over time, and — in pediatric cases — continued amblyopia management.

Prevention of aponeurotic ptosis is not reliably achievable, though avoidance of habitual eye rubbing and limiting prolonged hard contact lens wear may reduce levator aponeurosis stress. In children with congenital ptosis, regular ophthalmological surveillance from infancy is the most important preventive measure against amblyopia — early detection allows timely surgical intervention and amblyopia treatment. Post-surgical care involves topical antibiotic drops or ointment, cold compresses to reduce swelling, and avoidance of contact lens wear for 4–6 weeks. Lagophthalmos (incomplete eye closure) in the postoperative period requires intensive preservative-free lubricating drops and ointment at night to prevent exposure keratopathy. Suture adjustment under local anesthesia may be performed in the first 1–2 days postoperatively in procedures allowing this. Children with post-surgical amblyopia require ongoing occlusion therapy. Patients with myasthenia gravis-related ptosis must be monitored for myasthenic crisis during any surgical or perioperative period.

Sudden-onset unilateral ptosis accompanied by a dilated unreactive pupil, double vision, or downward and outward deviation of the eye is a neurological emergency requiring immediate evaluation to exclude a compressive posterior communicating artery aneurysm. Any child with a drooping eyelid — whether unilateral or bilateral — should be evaluated by an ophthalmologist as early as possible; even mild obstruction of the visual axis during the first 7–8 years of life can cause permanent amblyopia. Adults noticing progressive eyelid drooping affecting their superior visual field, causing brow ache, or resulting in head tilting should seek an oculoplastic or ophthalmological consultation. Ptosis that is variable — worsening with fatigue or prolonged upgaze — particularly when bilateral or accompanied by double vision, warrants urgent neurology evaluation for myasthenia gravis. Ptosis following eyelid trauma, surgery, or after hard contact lens use should be assessed by a specialist.