SOOF: the suborbicularis oculi fat
- Highlighted area
Quick facts
- Definition
- Deep fat pad just below the orbicularis oculi muscle, at the lower rim of the orbit.
- Location
- Over the bone of the lower orbital rim and the zygomatic bone, below the orbicularis retaining ligament.
- Parts
- Medial (from the inner edge of the iris to the outer corner of the eye) and lateral (from the outer corner toward the temple).
- Difference from the fat pads
- Lies outside the orbit, in front of the bone; the eyelid fat pads lie inside the orbit, behind the orbital septum.
- Relevance in facial harmonization
- Its loss and descent contribute to a visible orbital rim and to a marked transition between eyelid and cheek.
SOOF is the acronym for suborbicularis oculi fat. It is a deep fat pad that lies just below the orbicularis oculi muscle, resting on the bone of the lower rim of the orbit and the zygomatic bone. It helps create the smooth transition between the lower eyelid and the cheek, and its loss or descent takes part in the tired look of the gaze.
Where is it and what are its boundaries?
The SOOF is one of the deep fat pads of the face. The most common description divides it into two parts:
| Part | Approximate extent | Neighbors |
|---|---|---|
| Medial SOOF | From the inner edge of the iris (medial limbus) to the outer corner of the eye | Medially, the deep medial cheek fat; below, the region of the infraorbital foramen |
| Lateral SOOF | From the outer corner of the eye toward the temple | Laterally, the fat of the temporal region |
Above, the boundary is the orbicularis retaining ligament, which anchors the muscle to the bone at the orbital rim. In front is the orbicularis oculi muscle; behind, the periosteum of the bone. The boundaries are described approximately and vary between people.
How does the SOOF differ from the fat pads?
This is the most common confusion when assessing tear troughs. The eyelid fat pads lie inside the orbit, behind the orbital septum, and when they bulge they form the volume of the lower eyelid. The SOOF lies outside the orbit, below the muscle, over the bone. One tends to be in excess in front of the eye; the other tends to be lacking over the bony rim. The two situations can coexist in the same patient.
It should also not be confused with the ROOF (retro-orbicularis oculi fat), the fat behind the orbicularis in the brow region and upper eyelid.
Why does it matter in facial harmonization?
With aging, the SOOF tends to lose volume and descend, and the bone of the orbit also changes. The result is usually:
- a more visible lower orbital rim;
- a marked transition between eyelid and cheek, adding to the tear trough;
- shadow on the lateral part of the under-eye area and loss of support of the upper cheekbone.
That is why the assessment of tear troughs looks at the whole region, not only the medial groove. The indication for volume replacement in the area, the product and the technique are the decision of the qualified professional, after assessment. For the types of under-eye hollow and how to tell them apart, see under-eye circles: types and assessment.
How does it show up in the assessment?
- Light from above: highlights the shadow over the bony rim when support is lacking.
- Profile and three-quarter view: show the transition between eyelid and cheek.
- Looking up: accentuates the orbital fat pads, which helps tell a bag from a lack of volume.
- Morning swelling: puffiness that varies through the day calls for caution before any volume.
Also called: suborbicular fat, suborbicularis oculi fat.
Frequently asked questions
What is the SOOF?
It is the acronym for suborbicularis oculi fat: a deep fat pad just below the orbicularis muscle, over the lower rim of the orbit and the zygomatic bone.
Is the SOOF the same as the eye fat pad?
No. The fat pads lie inside the orbit, behind the orbital septum, and push the eyelid forward. The SOOF lies outside the orbit, in front of the cheek bone, and its loss usually leaves the area more hollow.