BACKGROUND: Understanding the anatomy of the lower eyelid, including the effect of aging, assists in blepharoplasty. METHODS: After celloidin was embedded, 30-mum-thick serial sagittal sections from the medial to the lateral canthus were prepared from two Japanese left lower eyelid specimens obtained from a young cadaver and an old cadaver. A comparative study was then performed. RESULTS: The orbicularis oculi muscle was divided into three portions. Each muscular portion was transformed by aging. The fascia group that maintained the orbicularis oculi muscle was observed. Particularly, the fasciae in the upper and lower portions were termed the "upper fascia" and "lower fascia," respectively. These fasciae were generically referred to as "suborbicularis retaining fasciae." The suborbicularis retaining fasciae relaxed with aging. Fat tissue was observed in front of the orbital septum and was termed "preseptal adipose tissue." This area was most sensitive to deep pressure, because the retaining fascia hardly exists here; it almost disappears with aging. The retinacula cutis connected the orbicularis oculi muscle and the skin in parallel; their palisade structure was not clear in the aged specimen. In both specimens, the tarsal muscle did not unite with the tarsus, and the muscle fiber was enlarged at the lateral border of the tarsus. CONCLUSION: Lower eyelid aging changes were involved in the transformation of the three parts of the orbicularis oculi muscle, the relaxation of the suborbicularis retaining fasciae, the disappearance of the preseptal adipose tissue area due to orbital fat herniation, and the indistinctness of the palisade structure of the retinacula cutis.
BACKGROUND: Understanding the anatomy of the lower eyelid, including the effect of aging, assists in blepharoplasty. METHODS: After celloidin was embedded, 30-mum-thick serial sagittal sections from the medial to the lateral canthus were prepared from two Japanese left lower eyelid specimens obtained from a young cadaver and an old cadaver. A comparative study was then performed. RESULTS: The orbicularis oculi muscle was divided into three portions. Each muscular portion was transformed by aging. The fascia group that maintained the orbicularis oculi muscle was observed. Particularly, the fasciae in the upper and lower portions were termed the "upper fascia" and "lower fascia," respectively. These fasciae were generically referred to as "suborbicularis retaining fasciae." The suborbicularis retaining fasciae relaxed with aging. Fat tissue was observed in front of the orbital septum and was termed "preseptal adipose tissue." This area was most sensitive to deep pressure, because the retaining fascia hardly exists here; it almost disappears with aging. The retinacula cutis connected the orbicularis oculi muscle and the skin in parallel; their palisade structure was not clear in the aged specimen. In both specimens, the tarsal muscle did not unite with the tarsus, and the muscle fiber was enlarged at the lateral border of the tarsus. CONCLUSION: Lower eyelid aging changes were involved in the transformation of the three parts of the orbicularis oculi muscle, the relaxation of the suborbicularis retaining fasciae, the disappearance of the preseptal adipose tissue area due to orbital fat herniation, and the indistinctness of the palisade structure of the retinacula cutis.