Related Experiment Video
Updated: Apr 16, 2026

Isolation of Intact Eyeball to Obtain Integral Ocular Surface Tissue for Histological Examination and Immunohistochemistry
Published on: October 20, 2019
Regional Variations in Orbicularis Oculi Histology
Bryan R Costin1, Thomas P Plesec, Laura J Kopplin
1*Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio and †Department of Anatomic Pathology, Cleveland Clinic, Cleveland, Ohio; ‡Casey Eye Institute, Oregon Health and Science University, Portland, Oregon; §Department of Anatomy, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio; ‖Lorain Institute, Cleveland Clinic, Lorain, Ohio.
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.
Related Concept Videos
Muscles of the Eye
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and...
Accessory Structures of the Eye
Muscles for Facial Expressions
Anatomy of the Eyeball
Microbiome of the Eye
Reticular Dermis
Reticular Layer
Underlying the papillary layer is the much thicker reticular layer, composed of dense, irregular connective...

