J Korean Ophthalmol Soc.  2009 Oct;50(10):1447-1454. 10.3341/jkos.2009.50.10.1447.

The Size of Extraocular Muscles Estimated by Computed Tomography in Patients Undergoing Orbital Wall Fracture Repair

• Kim HE
• Lew H
• Yun YS

• KMID: 2212759
• DOI: http://doi.org/10.3341/jkos.2009.50.10.1447

Abstract

PURPOSE
To determine the cross sections of extraocular muscles in patients with orbital fracture and to demonstrate a relationship among the cross sections, the size of orbital fracture, the soft tissue, and fat herniation and limitation of ocular movement.
METHODS
The study included 87 patients (87 eyes) with orbital fracture. The cross section was defined as multiplication of the long axis and short axis. The ratio of the cross section in normal and injured eyes was calculated at preoperative and postoperative periods.
RESULTS
The cross sections of all rectus muscles, except for the superior, increased in injured eyes and subsequently decreased postoperatively. After surgery, the cross sections of lateral and medial rectus muscles recovered to near normal but the inferior remained enlarged. The increased ratio of the short and long axis was significant but not the difference of the cross sections related to the short and long axis ratio. There was a preoperative difference between injured/normal cross section ratio in relation to the size of inferior fracture. There was postoperative normalization for the cross sections of inferior rectus muscles with the restrictive limitation due to inferior fracture.
CONCLUSIONS
The cross sections increased mostly after orbital fracture and subsequently decreased postoperatively. There was a change in the cross section ratio with the size of inferior fracture at preoperative period but there was no change in the cross sections related to the restrictive or paralytic limitation, except for eyes with the restriction secondary to inferior fracture. These were significantly normalized postoperatively in cross section.

Keyword

Extraocular muscle; Orbital fracture

MeSH Terms

Axis, Cervical Vertebra
Eye
Humans
Muscles
Orbit
Orbital Fractures
Postoperative Period
Preoperative Period

Figure

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  Figure 1. The measurement of extraocular muscles in preoperative normal (A), postoperative normal (B), preoperative injured (C) and postoperative injured eye (D).

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  Figure 2. The size of orbital wall fracture (arrow) classified into small (A, D), medium (B, E) and large (C, F) at inferior (A, B, C) and medial (D, E, F) orbital wall fracture.

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  Figure 3. The soft tissue and fat herniation (arrow) classified into small (A, D), medium (B, E) and large (C, F) at inferior (A, B, C) and medial (D, E, F) orbital wall fracture.

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  Figure 4. The restrictive limitation of ocular motion demonstrates the limitation of supraduction (white arrow)(A), restriction on HESS screen (black arrow) (B) and diplopia at binocular single vision test (C) in patient with inferior orbital wall fracture.

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  Figure 5. The paralytic limitation of ocular motion demonstrates the limitation of infraduction (white arrow)(A), restriction on HESS screen (black arrow) (B) and diplopia at binocular single vision test (C) in patient with inferior orbital wall fracture.

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  Figure 6. The cross section value in preoperative normal, postoperative normal, preoperative injuredand postoperative injured eyes of the extraocular muscles before and after open reduction of orbital wall fracture.

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  Figure 7. The cross section ratio between injuredand normal eyes in relation to the size of inferior orbital wall fracture at preoperative and postoperative period (* p value<0.05).

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  Figure 8. The cross section ratio between injured and normal eyes in relation to the size of medial orbital wall fracture at preoperative and postoperative period.

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  Figure 9. The cross section ratio between injured and normal eyes in relation to the extension of the soft tissue and fat herniation in patients with inferior orbital wall fracture at preoperative and postoperative period.

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  Figure 10. The cross section ratio between injured and normal eyes in relation to the extension of the soft tissue and fat herniation in patients with medial orbital wall fracture at preoperative and postoperative period.

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  Figure 11. The cross section ratio between injured and normal eyes in relation to the restrictive limitation of ocular motion in patients with inferior orbital wall fracture at preoperative and postoperative period(*p value<0.05).

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  Figure 12. The cross section ratio between injured and normal eyes in relation to the restrictive limitation of ocular motion in patients with medial orbital wall fracture at preoperative and postoperative period.

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  Figure 13. The cross section ratio between injured and normal eyes in relation to the paralytic limitation of ocular motion in patients with inferior orbital wall fracture at preoperative and postoperative period.

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  Figure 14. The cross section ratio between injuredand normal eyes in relation to the paralytic limitation of ocular motion in patient with medial orbital wall fracture at preoperative and postoperative period.

Reference

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