Ptosis, or blepharoptosis, is the name given to drooping of the eyelid. This may be due to mechanical causes, such as aponeurosis dehiscence, or neurological disease, in which case it may be congenital or acquired, partial or complete, unilateral or bilateral, fixed or variable, isolated or accompanied by other signs, e.g., miosis in a Horner’s syndrome; diplopia in myasthenia gravis; mydriasis and downward and outward deviation of the eye in an oculomotor (III) nerve palsy.
Ptosis may result from pathology in a variety of locations: brainstem disease involving the oculomotor (III) nerve; anywhere along the oculosympathetic autonomic pathway causing a Horner’s syndrome; or cortical disease (e.g., infarction) reflecting hemispheric control of the eyelid (probably bilaterally represented).
When considering the cause of ptosis, the differential diagnosis is broad. Recognized causes include:

  1. Congenital:

Cranial nerve dysinnervation disorder Congenital Horner’s syndrome
Oculomotor-trigeminal (or trigeminal-levator) synkinesis: Marcus Gunn jaw-winking phenomenon, or inverse Marcus Gunn phenomenon (ptosis on jaw opening).

  1. Neurogenic:

Supranuclear lesion:
Hemiparesis: due to cortical infarct; ptosis usually ipsilateral, incomplete
Duane syndrome: ptosis on eye adduction, due to supranuclear levator inhibition; usually with family history
Oculomotor (III) nerve:
Hypertension, diabetes: ptosis often complete; in a superior divisional third nerve palsy partial ptosis is associated with superior rectus weakness only Compressive lesion (e.g., posterior communicating artery aneurysm): ptosis usually incomplete; ptosis may be present with subarachnoid hemorrhage
Guillain-Barré syndrome Facial paresis

  1. Neuromuscular junction:

Myasthenia gravis: ptosis variable, bilateral or unilateral Excessive botulinum toxin, e.g., given for treatment of blepharospasm

  1. Myogenic: ptosis usually bilateral Mitochondrial disease (CPEO) Myotonic dystrophy

Oculopharyngeal muscular dystrophy (OPMD)

  1. Local, ophthalmological causes:

Age-related aponeurosis dehiscence, trauma, thyroid eye disease, lid inflammation (chalazion), lymphoma.
Pseudoptosis (q.v.) enters the differential diagnosis.
Enhanced ptosis, worsening of ptosis on one side when the other eyelid is held elevated in a fixed position, may be demonstrated in myasthenia gravis and Lambert Eaton myasthenic syndrome.



Caplan LR. Ptosis. Journal of Neurology, Neurosurgery and Psychiatry
1974; 37: 1-7


Cross References

Blepharospasm; Diplopia; Divisional palsy; Ewart phenomenon; Horner’s syndrome; Jaw winking; Miosis; Mydriasis; Pseudoptosis; Pupil sparing; Synkinesia, Synkinesis