Superior oblique tucks for apparent inferior oblique overaction and V-pattern strabismus associated with craniosynostosis

Abstract

Introduction: Apparent inferior oblique overaction and apparent superior oblique underaction are common in strabismus associated with craniosynostosis, and in many cases are likely due to excyclotorsion of the globes, with the rectus muscles acting with oblique vectors. We present a patient with craniosynostosis who underwent bilateral superior oblique tucks to specifically address the excyclotorsion of the globes.

Methods: A 16-year-old male with Saethre-Chotzen syndrome presented with apparent bilateral inferior oblique overaction and apparent bilateral superior oblique underaction. He had 30 prism diopter (PD) esotropia and 5 PD left hypertropia by simultaneous prism and cover test (SPCT) at distance and near fixation. Fundus exam revealed marked excyclotorsion of both globes. The superior oblique tendons were tucked 10 mm bilaterally, using a 6-0 mersilene suture and the medial rectus muscles were recessed 5.5 mm on an adjustable suture with a 10-mm inferior displacement. Surgical results were reviewed at 6 weeks and 2 years postoperatively.

Results: At 6 weeks and 2 years postoperatively, apparent inferior oblique overaction, apparent superior oblique underaction, and V-pattern esotropia were markedly improved. At 2 years, SPCT measurements were 8 PD esotropia in primary position at distance and 4 PD esotropia and 3 PD left dissociated vertical deviation at near.

Conclusions: Bilateral superior oblique tucks are useful in addressing the excyclotorsion that leads to apparent inferior oblique overaction and V-pattern strabismus associated with craniosynostosis.

Figure 1

Pre-operative versions showing apparent bilateral inferior oblique overaction (over elevation in adduction) and apparent bilateral superior oblique underaction (under depression in adduction), greater right eye than left eye.

Figure 2

Pre-operative fundus photographs showing bilateral excyclotorsion

Figure 3

Computerized tomography scan of the orbits showing relative excyclotorsion of each globe with medial rectus muscles more superior than normal and inferior rectus muscles more nasal.

Figure 4

Post-operative versions (2 years following surgery) showing improvement in apparent bilateral inferior oblique overaction (over elevation in adduction) and improvement in apparent bilateral superior oblique underaction (under depression in adduction).