Questions:
7. Is aponeurotic ptosis usually unilateral or bilateral?
8. What findings on an exam of the upper eyelid are likely to be present with aponeurotic ptosis?
9. What is the most common condition causing acquired ptosis in patients over age 50?
10. What usually causes acquired ptosis in young patients?
11. In addition to measuring eyelid positions and levator function, what 2 exam techniques should be performed in all patients with ptosis?
12. What condition must be ruled-out in all patients with presumed myogenic ptosis?
13. What is the hallmark of myasthenic ptosis?

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Questions with answers:
7. Is aponeurotic ptosis usually unilateral or bilateral?
Bilateral 

8. What findings on an exam of the upper eyelid are likely to be present with aponeurotic ptosis?
The eyelid crease is high or indistinct, and levator function is relatively well preserved.

9. What is the most common condition causing acquired ptosis in patients over age 50?
Aponeurotic ptosis

10. What usually causes acquired ptosis in young patients?
Contact lenses

11. In addition to measuring eyelid positions and levator function, what 2 exam techniques should be performed in all patients with ptosis?
Palpation and eversion of the eyelids 

12. What condition must be ruled out in all patients with presumed myogenic ptosis?
Myasthenia gravis 

13. What is the hallmark of myasthenic ptosis?
A fluctuation of the ptosis over time.

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The information below is from Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

Mechanical Ptosis
Aponeurotic ptosis (▶Fig. 17.8) is usually bilateral. The upper eyelid crease is high or indistinct, and levator function is relatively preserved. 

In elderly patients, an aponeurotic defect may be associated with dermatochalasis. The aponeurosis of the levator muscle dehisces or disinserted from the tarsal plate of the upper lid (usually bilateral). It is also common after ocular surgery requiring a speculum (usually unilateral). In younger patients, it is usually secondary to contact lens wear.

Pearls
Aponeurotic defect is the most common cause of acquired ptosis in adults.

Lesions of the eyelid (e.g., tumor, chalazion, and vascular malformations) can produce a mechanical ptosis (▶Fig. 17.9 and Fig. 17.10).

Pearls
Palpation and inversion of the eyelids should be performed in all patients with ptosis.

Myogenic Ptosis
Myogenic ptosis (▶Fig. 17.11 and Fig. 17.12) is usually bilateral and progressive. It is commonly associated with impaired eye movements. There may not be diplopia if the eyes are straight in primary position and if the ophthalmoplegia is complete. The pupils are always normal. Chronic progressive external ophthalmoplegia (mitochondrial disorder) is a classic cause.

Reference: 1. Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Thieme

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