A 68-year-old woman presents with gradually progressive bilateral upper lid ptosis over 3 years. Examination shows margin reflex distance-1 (MRD1) of 2 mm, levator function of 15 mm, and an elevated upper lid crease. The MOST likely diagnosis is:
- A Congenital myogenic ptosis
- B Aponeurotic ptosis ✓
- C Myasthenia gravis
- D Third cranial nerve palsy
Correct answer: B. Aponeurotic ptosis
Explanation
Aponeurotic (involutional) ptosis is characterized by good levator function (greater than 10 mm), an elevated or absent lid crease due to dehiscence or disinsertion of the levator aponeurosis, and occurs in elderly patients. Congenital ptosis shows poor levator function (less than 4 mm). Third nerve palsy presents with much larger ptosis and ophthalmoplegia. Myasthenia gravis causes variable, fatigable ptosis with normal levator function.
Reference: Myron Yanoff and Jay S. Duker: Ophthalmology, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.