Regional Variations in Orbicularis Oculi Histology.

Laura Kopplin // Publications // Mar 21 2015

PubMed ID: 25794026

Author(s): Costin BR, Plesec TP, Kopplin LJ, Chundury RV, McBride JM, Levine MR, Perry JD. Regional Variations in Orbicularis Oculi Histology. Ophthalmic Plast Reconstr Surg. 2015 Jul-Aug;31(4):325-7. doi: 10.1097/IOP.0000000000000430.

Journal: Ophthalmic Plastic And Reconstructive Surgery, Volume 31, Issue 4,

PURPOSE To investigate and compare the histologic compositions of the pretarsal, preseptal, and orbital orbicularis oculi muscle (OOM) using nonpreserved, fresh-frozen, human cadavers.

METHODS The OOM was exposed using sharp and blunt dissection. A metric ruler was used to measure and mark 0.5 cm × 1 cm samples from each portion of the right, superior OOM. Samples were excised, fixed in formalin, and completely embedded in paraffin. Five-micrometer-thick, hematoxylin- and eosin-stained sections were generated for each sample and analyzed by an anatomical pathologist. The relative percentages of the 4 main tissue types (skeletal muscle, fibrous tissue, adipose tissue, and neurovascular tissue) were quantified.

RESULTS Forty-two samples were obtained from 14 Caucasian cadavers. On average, the pretarsal samples were composed of 83.5% skeletal muscle, 0.0% adipose, 5.0% neurovascular, and 11.5% fibrous tissue. Average preseptal OOM was 46.5% skeletal muscle, 12.7% adipose, 9.2% neurovascular, and 31.5% fibrous tissue. The orbital OOM was, on average, 42.7% skeletal muscle, 32.7% adipose tissue, 6.9% neurovascular, and 17.7% fibrous tissue.

CONCLUSIONS The OOM represents a histologically heterogeneous structure.