Question
Right esotropia is evident with ‑
| A. |
Left lateral rectus paralysis |
| B. |
Right lateral rectus paralysis |
| C. |
Left medial rectus paralysis |
| D. |
Right medial rectus paralysis |
Show Answer
|
Correct Answer » B Explanation |
 |
Ans: Right lateral Rectus palsy
For each eye, six muscles work together to control eye position and movement. Two extraocular muscles, the medial rectus and lateral rectus, work together to control horizontal eye movements.
- Contraction of the medial rectus pulls the eye towards the nose (adduction or medial movement).
- Contraction of the lateral rectus pulls the eye away from the nose (abduction or lateral movement).
The actions of these two muscles are antagonistic: one muscle must relax while the other contracts to execute horizontal eye movements.
- Agonist → Main muscle that helps in the movement of the eyeball.
- Antagonist → The muscle that counteracts the agonist.
- Synergist → The muscle that supports agonist.
Hence, the answer is “B”, Right lateral rectus palsy resulting in unopposed action of the right medial rectus muscle. Left lateral rectus palsy causes left esotropia and not right esotropia.