Magnetic Resonance Imaging Demonstrates Differences in Brow and Upper Eyelid Fat and Muscle Layers Between East Asians and Caucasians

Retro-orbicularis oculi and frontalis fat is the major contributor to the anteroposterior thickness of the eyelid at the level of the superior orbital rim in both East Asians and Caucasians. In East Asians, the ROOF comprises much of the total width inferior to the superior rim, whereas the Caucasian eyelid is mostly muscular. In Caucasians, ROOF is centered around the rim and extends intra-orbitally onto the roof as opposed to East Asians in which it continues inferiorly, into the upper eyelid. These anatomic variations explain some of the differences in surface anatomy between ethnic groups.