Asian eyes differ from Western ones in their "structure" — and so the design of cosmetic surgery changes accordingly.
"My eyelids are naturally heavy and puffy," "I want a wide, natural double eyelid, but I want to avoid an unnatural result that obviously looks operated on" — many Asians who visit cosmetic surgery clinics hold such worries and wishes. In fact, do you know the simple fact that the decisive difference between a single eyelid and a double eyelid is whether or not just one particular "structure" is present?
Whereas the vast majority of Westerners are born with double eyelids, the proportion of Asians born with double eyelids is only about 50% (Wang et al. 2023). For that reason, in Asia, double eyelid surgery has become the most commonly performed cosmetic surgery. However, Western eyes and Asian eyes differ greatly in fundamental anatomical structures such as the thickness of the fat, the muscles, and the positional relationship of the aponeurosis. In this article, based on the latest medical knowledge and anatomical data, we explain in detail what is happening to Asian eyes and why Asians need a special surgical design.
The difference between single and double eyelids is not "the presence or absence of a single thread"
The fundamental difference between a single eyelid and a double eyelid is explained by the "levator aponeurosis expansion theory" (Wang et al. 2023). In people born with a double eyelid, the fibers of the levator aponeurosis penetrate the orbicularis oculi muscle and attach to the subcutaneous tissue of the skin (Wang et al. 2023). When the eyelid is opened, this aponeurosis contracts and is drawn in, and the attached skin is drawn in as well, forming the double-eyelid line. People with a single eyelid do not have this fiber structure connecting from the levator aponeurosis to the skin. In other words, surgery that creates a natural double eyelid is the work of artificially reconstructing this lost physiological connecting structure.
What is happening in the Asian upper eyelid — understanding the anatomy with illustrations
The difference in the attachment of the levator aponeurosis
In the case of Asians, the position where the orbital septum and the levator aponeurosis fuse is very low, and in Asians, who mostly have single eyelids, the fibers connecting from the levator aponeurosis to the skin barely exist. Furthermore, due to aging or long-term wearing of hard contact lenses, "acquired aponeuroticptosis," in which the aponeurosis detaches from or thins on the tarsal plate, can also occur.
The pre-orbicularis fat layer — the structural reason it tends to become a single eyelid
The Asian upper eyelid has abundant subcutaneous fat tissue such as ROOF (retro-orbicularis oculi fat) and preseptal fat. This thick fat layer, abundant orbital fat, and thick pretarsal subcutaneous tissue become physical obstacles and hinder the levator aponeurosis from extending to the skin. The thickness of this tissue, while forming a single eyelid, is also the cause of the puffy eyes characteristic of Asians.
What is the epicanthal fold?
The epicanthal fold (medial canthal epicanthus) is a fold of skin covering the inner corner of the eye, frequently seen in Asian patients with single eyelids. When this fold is taut, it makes the eye look smaller horizontally, or becomes a cause of the double-eyelid line hiding within the skin on the inner-corner side. When an ideal parallel-type double eyelid is desired, medial epicanthoplasty (inner-corner incision) is sometimes performed at the same time as the double eyelid surgery.
Why the Western upper blepharoplasty cannot be used on Asians as is
The Western-style incision method excises excess skin, orbicularis oculi muscle, and fat, and sutures the skin directly to the tarsal plate, but applying it to Asians as is results in a "deep, hard, sunken, unnatural double-eyelid line." The risk of leaving a scar with a remaining crease even when the eyes are closed also rises. If the thick ROOF or orbital fat characteristic of Asians is mishandled, the double-eyelid line becomes shallow or disappears after surgery.
Techniques evolved for Asians — the hinge technique and others
- The bridge technique and floating-bridge structure (Wong et al. 2022):A flap is created using the confluence of the orbital septum and the levator aponeurosis, and fixed to the tarsal plate to build a "bridge." It achieves a dynamic, flexible double eyelid that is drawn in only when the eye is opened, without relying on scar adhesion.
- Orbicularis-preserving / small-incision approach:A technique that preserves the orbicularis oculi muscle without excising it, and exposes and fixes the levator aponeurosis from a minute incision of about 2 mm (Wong et al. 2022). It prevents hollowing of the eyelid and forms a natural, supple double eyelid.
- The DOSF method:A technique that uses the SAJT (septoaponeurotic junction thickening) as an anchor for fixation. It avoids an overly deep crease and maintains a natural double eyelid that is resistant to loosening over the long term.
- Combining fat removal in the buried-suture method:Because thick ROOF or orbital fat becomes a barrier that physically hinders thread fixation, it has been proven that removing fat from a minute needle hole can statistically significantly lower the risk of thread loosening and reoperation.
Why revision surgery is difficult — why the initial design is important
Because of the scarring produced by the first surgery and the distortion of the anatomical structure, revision surgery is far more difficult than the first (Chen et al. 2004). The normal layered structure has been destroyed by adhesions, and accurately dissecting and identifying the levator aponeurosis and tarsal plate becomes markedly difficult.
Preoperative asymmetry is also a factor that sends the reoperation risk soaring. Patients with a difference of 1 mm or more in MRD1 have a reoperation rate of 42.7% (Chen et al. 2004) (28.1% for symmetrical people). Due to Hering's law, operating on one side upsets the balance of the other side, so adjusting left and right is extremely difficult.
Furthermore, tissue laxity due to aging, and cases where the ROOF characteristic of Asians has not been appropriately handled, also become causes of the line loosening. That is precisely why the "initial meticulous design" in the first surgery is more important than anything.
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Summary of this article
- The difference between single and double eyelids is the presence or absence of an anatomical connection:Whether the attachment of the levator aponeurosis to the skin exists is the decisive difference.
- The Western style is unsuited to Asians:Asian eyelids have thick ROOF and subcutaneous tissue and a different structure, so applying a Western-oriented incision method as is results in an unnatural double eyelid.
- The evolution of the latest techniques:Techniques that create a dynamic, natural double eyelid based on anatomy — the bridge technique, the DOSF method, orbicularis-preserving incision, and so on — are advancing.
- The design of the first surgery decides everything:Revision surgery is extremely difficult due to the effects of scarring and Hering's law, so the meticulous design of the first surgery is the key to success.
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References
- Wong C, Hsieh M, Wei F. Asian Upper Blepharoplasty with the Hinge Technique. Aesthetic Plastic Surgery. 2022 DOI
- Wang C, Pu L. Asian Upper Blepharoplasty. Clinics in Plastic Surgery. 2023 DOI
- Chen S, Mardini S, Chen H, et al. Strategies for a Successful Corrective Asian Blepharoplasty after Previously Failed Revisions. Plastic and Reconstructive Surgery. 2004 DOI
- Kure K. A simple and durable way to create a supratarsal fold (double eyelid) in Asian patients. Aesthetic Surgery Journal. 2001 DOI
Author of this article
Hiromitsu Nakamura Physician
Zetith Beauty Clinic Ginza, Osaka, Fukuoka
He has a track record of research presentations at domestic and international academic conferences, and is also engaged in technical guidance and education for Zetith Beauty Clinic as a whole. He specializes in precise aesthetic medicine based on anatomical grounds, pursuing natural results tailored to each person's bone structure and tissue.