Korean Under-Eye Bags: When Filler Works Instead of Surgery

I'm Dr. Jong Seon Kim, a director at Gangnam HERA in Seoul. I sit on the boards of the Korean Society of Aesthetic Surgery and the International Petit Medical Society, and I am a full member of the Korean Society of Oculoplastic Surgery — so the eye area is a big part of my day. In this video my colleague Dr. Jong Hoon Lee and I looked at three real under-eye cases from our clinic, each of which could have gone to surgery, and talked through why we chose filler instead.

My short answer: many "under-eye bags" are a small fat bulge sitting above a hollow groove. Filling the groove can make the bulge look much smaller without surgery — but a large fat bag is still a surgical problem, and dark circles do not always clear completely.

What are under-eye bags, really?

In most patients I see, the "bag" is two things side by side: a fat bulge on top and a hollow groove just below it. The bulge casts a shadow into the groove, and together they make the eyes look tired, older and darker than they are. Patients usually ask about the bulge. Very often, though, it is the groove that makes the bulge so visible.

That is why the same eyes can be approached two ways. Surgery takes the bulge away or moves it. Filler smooths the groove beneath it, so the step between bulge and hollow becomes gentle and the shadow shrinks. Which one makes sense depends on how big the bulge is, how deep the hollow is, how thin the skin is and — just as important — what the patient wants.

Can filler help a hollow left after eyelid surgery?

Yes. When a previous operation has left a hollow, filling the hollow is often simpler and more sensible than operating again. Our first case was an older patient who had clearly had under-eye surgery before. The fat was gone, but a deep groove had formed, which made her look older and made her dark circles look worse.

A second operation would mean dealing with scar tissue from the first one, and the problem was no longer the bulge — it was the hollow. So we filled the groove with filler. In the after-photo you can still see the small tape where we treated, and the groove is gone. She was very satisfied.

For this patient we also added Rejuran. You can see the small raised dots it leaves just after treatment. Filler restores volume, but it does not improve thin, tired skin. Rejuran is aimed at skin quality, so the two together treated both the shape and the surface. If you want to see what that looks like over time, Rejuran under-eye before and after shows the changes I would expect.

Is filler enough for a small bulge with thin skin?

Often, yes — and for this kind of patient surgery can be the less satisfying choice. Our second case is very common: a young patient with a mild fat bulge, a slight hollow under it, and dark circles sitting right in that hollow.

When we looked closely, the bulge was not large. Surgery would have been a borderline call. Her skin was also very thin — you could see blood vessels showing through, along the bridge of the nose as well as under the eyes. With skin like that, some darkness can still show through even after the hollow is filled. Add the fact that she did not want surgery and wanted a simpler way to improve, and filler was the right fit.

After treatment the area was smooth. The dark circles were not completely gone, but they were clearly better, and she was very happy with the result.

Why might dark circles not disappear completely?

Because a dark circle can have several causes, and filler only treats the one that comes from a hollow. If the darkness is a shadow, filling the hollow removes most of it. If the skin is very thin and the vessels show through, or if there is pigmentation, some of that color stays.

Dr. Lee and I agree on how we explain this at consultation. Some patients improve almost completely. Others improve by something like 70 percent. It is better to know that before treatment than to expect the eyes to become perfectly bright. When the cause is mixed, we sometimes combine approaches — filling, surgery, laser or Rejuran — but even then, I would not promise a 100 percent result. A clear improvement is a realistic goal; a perfect erase is not.

Can filler replace surgery for a fat bulge?

Sometimes it can give a result close to surgery — but not always, and two doctors can reasonably disagree on the same eyes. Our third case was a young woman with a clear fat bulge under each eye, darkness below it and a hollow next to it. She actually came to see Dr. Lee and asked for surgery.

That day Dr. Lee was fully booked, so I saw her instead. I suggested we try filling the hollow first. After filler, the bulging look was much reduced, and she decided not to have surgery for now.

Dr. Lee's honest reaction in the video is worth repeating: in a case like hers, he said he would probably have suggested surgery first. He also agreed that the filler result came close to what surgery would have achieved. That is the real picture. For a bulge of her size, filler and surgery were both reasonable, and she could choose the simpler one. For a larger bulge, I would not push filler.

What does under-eye filler involve at HERA?

A careful assessment, a small amount of filler placed with a fine cannula, and about 30 minutes in the chair. In practice it works like this:

1. Look at the cause first. I check the size of the fat bulge, the depth of the hollow, how thin the skin is and whether pigmentation is part of the darkness.
2. Decide honestly between filler and surgery. If the bulge looks surgical, I will tell you, and Dr. Lee can give his opinion too.
3. Small amounts, placed precisely. Under-eye skin is the thinnest on the face, so I use a blunt micro-cannula and small, evenly spread amounts to avoid lumps or a bluish tint.
4. Treat the skin separately if needed. When the skin itself is thin and tired, Rejuran can be added — it works on a different problem from filler.

Numbing cream is used, and local anesthesia if needed. Because the skin is so thin, mild swelling or a small bruise can appear; it can be covered with concealer and usually settles within about a week. HERA's domestic hyaluronic acid fillers generally last around 6–12 months and imported ones around 12–18 months. You receive an itemized written estimate before anything is injected, and an English interpreter is with you throughout.

The honest limits

Filler does not remove fat, and placed badly under the eye it can make things worse. Too much product or the wrong layer can leave a puffy or lumpy look, and filler can drift over time — why under-eye filler migrates and how it is fixed explains this in detail. If the fat bag is large, a surgical approach is the more honest answer; under-eye fat repositioning covers what that route involves.

What I like about these three cases is that none of them needed a dramatic answer. The right amount of filler in the right place gave each patient a fresher, less tired look and let them get on with their trip. If you would like to see more results, our before-and-after gallery shows real HERA patients.