ptosis
Pronunciation: TOE-sis
Drooping of the upper eyelid that may obstruct vision or create aesthetic concerns.
Full Definition
Ptosis refers to the drooping or falling of the upper eyelid, which can be congenital or acquired. Congenital ptosis results from developmental abnormalities of the levator muscle, while acquired ptosis may develop due to aging, trauma, neurological conditions, or previous surgery. The condition is classified by severity (mild, moderate, severe) based on the degree of pupil coverage and measured by margin-reflex distance (MRD). Surgical correction involves various techniques including levator resection, Müller's muscle-conjunctival resection, or frontalis suspension, depending on levator function and ptosis severity.
Usage
Usage note: Distinguish from dermatochalasis (excess skin) and pseudoptosis (apparent drooping from other causes).
In Context
- "The patient presented with severe congenital ptosis affecting the visual axis." — ophthalmology consultation
- "Levator function testing revealed poor function requiring frontalis suspension for ptosis correction." — pre-operative evaluation