Orbicularis oculi: morphological changes mimicking mitochondrial cytopathy in a series of control normal muscles.

Abstract

INTRODUCTION:

  Orbicularis oculi (OO) muscle has recently proposed as a suitable muscle for biopsy to diagnose mitochondrial cyopathy:

METHODS:

  Enzyme histochemical and immunohistochemical studies were performed on OO muscle obtained from 18 patients aged 37-87 years (median 64 years), 6 males, 12 females, who were undergoing routine upper blepharoplasty surgery.

RESULTS:

  We confirmed the marked type II fibre (fast myosin heavy chain) predominance (89%) but also noted a different proportion and distribution of mitochondria in these fibres with occasional pseudo-'ragged-red' fibres with prominent subsarcolemmal and cytoplasmic aggregation of mitochondria. Cytochrome oxidase-negative fibres and true 'ragged-red' fibres were found at all ages over 40 years at levels that approach those used for diagnosis of mitochondrial cytopathy in peripheral or limb skeletal muscles.

CONCLUSION:

  We would therefore urge caution in the use of OO as muscle biopsy for diagnosis of mitochondrial cytopathy and advise concomitant biopsy of limb skeletal muscle and/or supplementary genetic studies.

• Authors: Penelope McKelvie, Khami Satchi, Alan A McNab, Paul Kennedy
• Journal: Clinical & experimental ophthalmology (Clin Exp Ophthalmol) Vol. 40 Issue 5 Pg. 497-502 (Jul 2012) ISSN: 1442-9071 [Electronic] Australia
• PMID: 22044520 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

Chemical References

• Protein Isoforms
• Electron Transport Complex IV
• Myosin Heavy Chains

Topics

• Adult
• Aged
• Aged, 80 and over
• Biopsy
• Blepharoplasty
• Electron Transport Complex IV (metabolism)
• Female
• Humans
• Immunoenzyme Techniques
• Male
• Middle Aged
• Mitochondria, Muscle (enzymology, pathology)
• Mitochondrial Myopathies (diagnosis, enzymology)
• Muscle Fibers, Fast-Twitch (metabolism, pathology)
• Muscle, Skeletal (pathology)
• Myosin Heavy Chains (metabolism)
• Oculomotor Muscles (enzymology, pathology)
• Protein Isoforms