Key Difference – Ptosis vs Pseudoptosis
The drooping of the upper eyelid is identified as ptosis is medical terms. True ptosis is due to a nerve lesion or an abnormality in the muscles that are responsible for moving the eyelid up. However, there is no any underlying neurological or muscular abnormality in pseudoptosis. This is the key difference between ptosis and pseudoptosis. Its commonest cause is Dermatochalasis.
CONTENTS
1. Overview and Key Difference
2. What is Ptosis
3. What is Pseudoptosis
4. Similarities Between Ptosis and Pseudoptosis
5. Side by Side Comparison – Ptosis vs Pseudoptosis in Tabular Form
6. Summary
What is Ptosis?
Ptosis is the drooping of the upper eyelid. The upper eyelid movements are controlled by two muscles. Levator palpebrae superioris, which is the major muscles involved in the movement of the eyelid, is innervated by the oculomotor nerve. Muller muscle also takes part in moving the eyelid and has a sympathetic innervation. Since levator palpebrae superioris is predominantly involved in lifting up the upper eyelid, damage to the oculomotor nerve gives rise to a complete paralysis and a problem with the sympathetic nervous system will cause only partial ptosis.
Causes of Ptosis
- Oculomotor nerve palsy
- Horner’s syndrome
- Myasthenia gravis
- Chronic progressive external ophthalmoplegia
- Oculopharyngeal muscular dystrophy
- Involutional ptosis
- Edema and inflammation of the eyelid
Different investigations are carried out according to the clinical suspicion of the underlying cause. Management also varies depending on the pathology that causes ptosis.
Figure 01: Ptosis
The common investigations carried out when a patient suffers from ptosis include,
- Myasthenia antibody test
- CT scan of the brain
- Muscle biopsy
What is Pseudoptosis?
In pseudoptosis, although the upper eyelid appears to be drooped, there is no abnormality either in the muscles or the aponeurosis. Dermatochalasis is the commonest cause of pseudoptosis. When pseudoptosis is suspected, the eyelid can be lifted up manually to assess the margin of it which is not displaced in pseudoptosis.
Other Causes of Pseudoptosis
- Unilateral upper lid retraction
- Enophthalmos
Management
- Surgical correction is necessary when the pseudoptosis is due to dermatochalasis.
What is the Similarity Between Ptosis and Pseudoptosis?
- Both conditions are characterized by the drooping of the upper eyelid.
What is the Difference Between Ptosis and Pseudoptosis?
Ptosis vs Pseudoptosis |
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| Drooping of the eyelid is associated with a nerve lesion or an abnormality of the muscles. | There are no associated nerve lesions or muscular abnormalities. |
| Eyelid | |
| When the eyelid is manually lifted, we can observe that the eyelid margin has moved down. | In pseudoptosis, the eyelid margin is not displaced. |
Summary – Ptosis vs Pseudoptosis
Ptosis is the drooping of the upper eyelid. In true ptosis, eyelid droops either due to a nerve lesion or due to an abnormality in the muscles. But in pseudoptosis, there are no such lesions. This is the main difference between ptosis and pseudoptosis.
Reference:
1. Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders, 2009.
Image Courtesy:
1. “Phineas Gage GageMillerPhoto2010-02-17 Unretouched Color Cropped” By Author of underlying work unknown. – File:PhineasPGage.jpg (Public Domain) via Commons Wikimedia