Objective: To investigate the anatomophysiologic aging-related changes in the orbicularis oculi muscle.

Methods: We examined the full-thickness histologic characteristics of the upper eyelids from cadavers of 30-, 40-, 60-, and 70-year-old men and the muscle interference pattern (IP) of 68 healthy volunteers of both sexes aged 18 to 73 years.

Results: Histologic analysis revealed that in the aging upper eyelid, changes were primarily in the skin and subcutaneous layers with the characteristic loss of collagen elastic fibers; however, the whole muscle layer was histologically intact, with no signs of aging; loss of fibers, loss of adherence to surrounding structure, or ptosis. Neurophysiologic studies of the electromyographic IP of the orbicularis oculi muscle confirmed that the full efficiency of orbicularis oculi function was intact in the age group studied (18-73 years) in both sexes.

Conclusion: Our results suggest that the anatomophysiologic characteristics of the orbicularis oculi muscle remain intact through advancement of age.