**Core Concept**
Duane retraction syndrome is a congenital cranial dysinnervation disorder characterized by a spectrum of ocular motor abnormalities, primarily affecting the lateral and medial rectus muscles. It is classified into three types based on the presence and severity of the motility impairment.
**Why the Correct Answer is Right**
Duane retraction syndrome Type 3 is associated with a complete or nearly complete absence of the lateral rectus muscle, which results in a significant limitation of both adduction and abduction of the affected eye. This is due to the abnormal development of the nerve fibers that innervate the lateral rectus muscle, leading to a severe impairment in eye movement. The retraction of the globe upon adduction is also a characteristic feature of this condition.
**Why Each Wrong Option is Incorrect**
**Option A:** Duane retraction syndrome Type 1 is characterized by a limitation of abduction, but adduction is relatively preserved.
**Option B:** Duane retraction syndrome Type 2 is characterized by a limitation of adduction, but abduction is relatively preserved.
**Option D:** Double elevator palsy is characterized by a limitation of elevation, but adduction and abduction are relatively preserved.
**Clinical Pearl / High-Yield Fact**
Duane retraction syndrome is a classic example of a congenital cranial dysinnervation disorder, which highlights the importance of a thorough ophthalmological examination in diagnosing and managing patients with complex ocular motility disorders.
β Correct Answer: C. Duane retraction syndrome Type 3.
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