Which muscle is NOT among the most commonly affected extraocular muscles in Thyroid Eye Disease?

Which muscle is NOT among the most commonly affected extraocular muscles in Thyroid Eye Disease?

• A. Lateral rectus
• B. Superior rectus
• C. Medial rectus
• D. Inferior rectus

Answer: (A)

In Thyroid Eye Disease, inflammation and fibrosis tend to hit certain extraocular muscles more often than others. The inferior rectus and the medial rectus are the ones most commonly affected, with the superior rectus also involved sometimes. The lateral rectus is less commonly involved, making it the muscle that’s not typically affected in this pattern. So, the lateral rectus is the best answer. Clinically, this pattern explains why upgaze is often restricted (due to inferior rectus) and adduction is limited (due to medial rectus), while lateral movement is relatively spared.

In Thyroid Eye Disease, inflammation and fibrosis tend to hit certain extraocular muscles more often than others. The inferior rectus and the medial rectus are the ones most commonly affected, with the superior rectus also involved sometimes. The lateral rectus is less commonly involved, making it the muscle that’s not typically affected in this pattern. So, the lateral rectus is the best answer. Clinically, this pattern explains why upgaze is often restricted (due to inferior rectus) and adduction is limited (due to medial rectus), while lateral movement is relatively spared.