Eyelid fat pads: the anatomy behind under-eye bags
- Highlighted area
Quick facts
- Definition
- Fat inside the orbit that, when it pushes forward, forms the bulge of the eyelid.
- Location
- Behind the orbital septum, between the eyelid and the eyeball.
- Lower eyelid
- Three compartments: medial, central and lateral.
- Upper eyelid
- Two compartments: medial and central; the lacrimal gland sits laterally.
- Relevance in HOF
- Telling a fat pad apart from lack of volume and from swelling decides whether the case is for HOF, for surgery or for neither.
Eyelid fat pads are the fat inside the orbit that, with age or by constitution, pushes forward and forms a bulge in the eyelid. This fat sits behind the orbital septum, a thin membrane that runs from the bony rim of the orbit to the eyelid. When the septum and the tissues that hold the fat lose firmness, the fat moves forward and shows up as the "bag" under the eye, which patients usually call dark circles.
How many compartments do the eyelids have?
| Eyelid | Compartments | What separates them |
|---|---|---|
| Lower | Medial, central and lateral | The inferior oblique muscle separates the medial from the central; a band of tissue (arcuate expansion) separates the central from the lateral |
| Upper | Medial and central | The central compartment lies in front of the muscle that lifts the eyelid; the lacrimal gland sits laterally |
The medial fat is usually paler and firmer than the central fat. This division explains why fat pads are not always uniform: a person may have only the medial pad prominent, for example.
Why do fat pads appear?
- Aging: the orbital septum and the orbicularis oculi muscle lose tone, and the fat moves forward.
- Constitution: in some families, fat pads appear early, even in youth.
- Changes around them: volume loss below the orbital rim, as in the SOOF, and a deeper tear trough make the fat pad more visible by contrast.
It is important to tell a fat pad apart from other bulges in the area: swelling that varies through the day, puffiness of the cheekbone area and fluid buildup below the orbicular retaining ligament. Each has a different cause and approach.
Where is the line between HOF and surgery?
Filler does not remove fat. What it can do, in selected cases, is smooth the transition between the fat pad and the cheek, camouflaging a mild step. With prominent fat pads, adding volume below them tends to make the area heavier, and hyaluronic acid, because it attracts water, can worsen the puffiness.
Removing or repositioning the fat is done with eyelid surgery (blepharoplasty). Who may perform each procedure depends on the rules of each professional board: check yours.
How does it show up in the assessment?
- Looking up: the lower fat pad usually becomes more noticeable; the depression of a hollow does not.
- Light from above: the fat pad casts a shadow just below itself.
- Variation during the day: swelling that improves through the day suggests edema, not just fat.
- Lower eyelid distraction test: a slow snap-back indicates laxity.
- Old photos: they show whether the fat pad is recent or constitutional.
To tell the types of under-eye concerns apart, see under-eye circles: types and assessment and the lower eyelid area.
Also called: eyelid bags, under-eye fat bags, orbital fat herniation, orbital fat pseudoherniation.
Frequently asked questions
Does tear trough filler get rid of an eyelid fat pad?
No. Filler does not remove fat. In selected cases, smoothing the transition below a mild fat pad can camouflage the step, but with prominent fat pads the added volume usually makes things look worse. Removing or repositioning the fat is surgical.
How can I tell if the under-eye issue is a fat pad?
A fat pad forms a bulge below the eye that usually becomes more noticeable when the patient looks up. A hollow under-eye is a depression; pigmented under-eye circles are a color change. Often more than one component is present.