Intermediate
Technical
IVT
ptosis
Pronunciation: /ˈtoʊsɪs/
Drooping of the upper eyelid, often indicating neuromuscular junction or cranial nerve pathology.
Full Definition
Ptosis refers to the drooping or falling of the upper eyelid due to weakness of the levator palpebrae superioris muscle or its innervation. In neuromuscular medicine, ptosis is a key clinical sign seen in conditions affecting the neuromuscular junction (myasthenia gravis), cranial nerve III (oculomotor nerve), or muscle disorders. The degree and pattern of ptosis provide diagnostic clues.
Usage
Usage note: Distinguish from proptosis (eye protrusion) and blepharospasm (eyelid spasm).
In Context
- "Bilateral ptosis worsened throughout the day, suggesting myasthenia gravis." — Clinical observation
- "Ice pack test temporarily improved ptosis, supporting neuromuscular junction disorder." — Bedside examination
Also known as
eyelid drooping
Contrasted with
lid retraction
Don't confuse with
proptosis
blepharospasm