Interlower and postlower eyelid retractor fat pads: a cadaveric microscopic study.

Background To report the histological microscopic anatomy of the interlower and postlower eyelid retractor (LER) fat pads. Methods In this experimental microscopic study, 31 exenterated orbits from 31 Japanese cadavers (19 right and 12 left; 15 male and 16 female; mean age of death, 81.08.8 years; range, 52-97 years) fixed in 10% buffered formalin were used. Masson trichrome was used to stain sagittal full sections of exenterated tissues. Microscopic examination of the lower eyelids was carried out. Results The exenterated orbits demonstrated the presence of the histological existence of inter-LER fat pad (80.6%) and post-LER fat pad (22.6%) in the lower eyelids. The inter-LER fat pad was thick and located between the anterior and posterior layers of the LER, where the blood vessels passed through in 18 specimens (72.0%). The post-LER pad was thin, subtle and located between the posterior layer of the LER and conjunctiva. Conclusion This study reports a novel finding of the inter-LER and post-LER fat pads. Awareness of these fat layers provides surgeons with additional anatomical detail of lower eyelid anatomy.