Muscle Belly Union for Treatment of Myopic Strabismus Fixus

Abstract

Purpose: To evaluate the surgical results of the medial rectus (MR) muscle recession associated with longitudinal splitting of the lateral rectus (LR) and superior rectus (SR) muscles and surgical union of their corresponding midpoints in highly myopic patients with severe esotropia and hypotropia and restricted abduction and elevation. Methods: Six cases of severe high myopic strabismus fixus were considered with more than 90Δ esotropia and 25Δ to 30Δ hypotropia. The nasally deviated SR muscle and inferiorly shifted LR muscle were confirmed by MRI or CT scan. Supratemporal herniation of the globe from the muscle cone was also found by imaging. The LR and SR muscles were split in half from the insertion to past the equator. The lateral half of the SR muscle was united to the superior half of the LR muscle. Medial rectus muscle was recessed also. Results: Motility gradually improved and by 8 weeks in four cases there was 5Δ to 15Δ residual esotropia and no hypotropia and mild limitation in abduction and elevation. In two cases due to marked residual esotropia, we performed a second operation, and 2 months later residual esotropia was mild. Conclusion: In highly myopic patients, if the deviant paths of the LR and SR muscles are demonstrated by MRI or CT scan, the surgical method described is effective and recommended.

KEYWORDS:

• muscle belly union
• high myopia
• strabismus fixus
• estropia
• hypotropia