J Korean Ophthalmol Soc.  2009 Oct;50(10):1576-1581. 10.3341/jkos.2009.50.10.1576.

The Changes in Extraocular Muscles in Horner's Syndrome of Rats

• Song JH
• You WS
• Chung IY
• Seo SW

• KMID: 2212778
• DOI: http://doi.org/10.3341/jkos.2009.50.10.1576

Abstract

PURPOSE
The aim of this study was to understand the pathogenesis of the enophthalmos of Horner's syndrome. METHODS: We performed right cervical sympathectomy in 10 Sprague-Dawley rats weighing 200~300 grams at 8 weeks of age. We obtained bilateral extraocular muscle and fat from all 10 rats. These tissues were observed under light and electron microscopy.
RESULTS
After 8 weeks, ptosis and enophthalmos were seen in the right eye in all rats. We found no change bilateral fat, but the right extraocular muscle fibers had smaller diameters than the left. The right intermuscular distance was longer than the left upon light microscopy and the right extraocular muscle contained fewer and smaller mitochondria than the left extraocular muscle upon electron microscopy.
CONCLUSIONS
Based on these results, it is believed that enophthalmos resulted from extraocular muscle atrophy that resulted from decreasing metabolism of mitochondria in Horner's syndrome. However, enophthalmos in Horner's syndrome requires more intensive study.

Keyword

Cervical sympathectomy; Enophthalmos; Horner's syndrome

MeSH Terms

Animals
Enophthalmos
Eye
Horner Syndrome
Light
Microscopy
Microscopy, Electron
Mitochondria
Muscles
Muscular Atrophy
Rats
Rats, Sprague-Dawley
Sympathectomy

Figure

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  Figure 1. Right cervical sympathectomy was done in the rats.

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  Figure 2. Pre-operative (A) and post-operative 8 weeks (B) of case 1 showed drooping of the upper lid and enophthalmos in the right eye.

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  Figure 3. Light microscopy of the left rectus muscle (A) and right rectus muscle (B) at postoperative 8 weeks. It found that right extraocular muscle fibers had smaller diameter and wider interval than left. (Toluidine blue ×200) (☆ : intermuscular distance)

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  Figure 4. Difference of the right and left muscle fiber diameters (A) and of the right and left intermuscular fiber distance (B).

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  Figure 5. Transmission electron-microscopy of the left rectus muscle (A) and right rectus muscle (B) at post-operative 8 weeks, the right rectus muscle (B) showing smaller mitochondria size and less mitochondria number. (×12,000).

Reference

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