The pretarsal fat compartment in the lower eyelid

초록

It is generally accepted that there are three infraorbital fat compartments in the lower eyelid; medial, central and lateral compartment. However, removing only the fat in lateral compartment does not rid of the bulge just below the eyelashes. We found that there is fat pad which makes the knoll on the skin just below the eyelashes. The aim of this study is to describe an accurate anatomy of the pretarsal fat compartment and to demonstrate its clinical implications in lower lid blepharoplasty. Ten cadavers (total 20 lower eyelids) were subjected in the study. A skin-muscle flap was developed to expose the soft pretarsal structure. A small stab incision was made on the lateral portion of the sac containing fat on the tarsus. Methylene blue dye was injected into the sac. The specimens were fixed and sagittal sections on four different planes were prepared for histological slides and reviewed microscopically. The injected dye lodged within the sac and demarcated it in a pear or cone shape. It sits on the lateral half of the tarsal plate above the lateral compartment fat. Some researchers previously noted auxillary fatty structure without mentioning its covering sac. We have named it the "Pretarsal fat compartment". Histologically, the orbital septal fibers separate the "Pretarsal fat" and lateral infraorbital fat compartment. It is recommended to remove the fat in the pretarsal fat compartment in order to alleviate the bulge or knoll of the skin just below the lower eyelashes in the procedure of lower lid blepharoplasty.