3d. Paralytic Squint Flashcards
(15 cards)
What is paralytic squint?
A deviation of the eye due to paralysis of one or more extraocular muscles
What is the most common cause of acquired paralytic squint in adults?
Microvascular ischemia (e.g., diabetes, hypertension)
Which cranial nerve is most commonly involved in isolated ocular motor palsy?
Sixth nerve (abducens)
What is the hallmark of paralytic squint?
Incomitant deviation (angle varies in different gazes)
What is diplopia charting used for in squint evaluation?
To localize the paralyzed muscle based on double vision pattern
What is the Bielschowsky head tilt test used to diagnose?
Superior oblique palsy (4th nerve palsy)
What happens to the affected eye in 3rd nerve palsy?
Eye is ‘down and out’ with ptosis and dilated pupil
What does limitation of movement in both directions with pain suggest?
Orbital pathology or entrapment (not pure nerve palsy)
What is the most common cause of 4th nerve palsy?
Trauma
What is the characteristic feature of 6th nerve palsy?
Inability to abduct the eye
What is the head posture seen in 6th nerve palsy?
Face turned toward the affected side
In 3rd nerve palsy, which muscle is spared if the pupil is spared?
Parasympathetic fibers (superficial) are spared — medical emergency less likely
What investigation is crucial in 3rd nerve palsy with pupil involvement?
MRI/CT to rule out aneurysm
What is the typical sign of congenital 4th nerve palsy?
Long-standing head tilt to the opposite side
What muscle is commonly trapped in orbital floor fracture leading to restrictive strabismus?
Inferior rectus
