Medial epicanthoplasty (inner corner surgery): techniques and scarring

What is the epicanthal fold?

The epicanthal fold is a fold of skin that covers the inner corner of the eye and blends naturally into the skin of the nose. It is described as a feature of appearance seen in many populations around the world ^[1]. It is common in East Asian people and, anatomically, is said to be made up of the preseptal part of the muscle around the eye (orbicularis oculi muscle) ^[2].

Surgical methods for changing this structure were originally developed in the West to correct epicanthal folds that accompany congenital conditions such as Down syndrome ^[1]. Cosmetic surgery came later, and today the procedure is mostly performed on and by people of East Asian descent, with most of the related research also written by East Asian authors ^[1].

Why it is discussed alongside double eyelid surgery

As research on East Asian eyelids has grown, understanding of the clinical significance of the epicanthal fold has deepened ^[2]. One review stressed that to get good results in upper eyelid surgery for East Asian patients, whether an epicanthal fold is present and how to correct it should be discussed first ^[2].

Another comprehensive review of upper eyelid surgery in East Asian patients included, along with setting the height and length of the crease and refining the eyelid structures, a step of adding epicanthoplasty when needed to improve the cosmetic result ^[5]. However, this is an option only when needed; not every double eyelid surgery requires epicanthoplasty ^[5].

Types of epicanthoplasty technique

A study that traced trends in the research on epicanthoplasty analyzed 46 papers ^[3]. Of these, 43 (93.5%) covered methods for removing the epicanthal fold, and 3 (6.5%) covered methods for recreating a fold that had already been removed ^[3].

The 48 techniques analyzed were, in order, Z-plasty in 21 cases (43.8%), advancement flaps in 14 (29.2%), excision in 7 (14.6%), and skin redraping in 4 (8.3%) ^[3]. Z-plasty was reported to be used more and more over time, excision declined to the point that no recent papers had described it, and skin redraping had recently increased ^[3].

A systematic review of the literature from 2012 to 2018 also reported 8 studies on Z-plasty and its variations, 4 on advancement flaps, and 1 on skin redraping, while methods that remove or release the orbicularis muscle were covered in 14 studies ^[4]. Broadly grouped by flap shape, the techniques can be divided into two types: advancement flaps and transposition flaps ^[2].

What determines scarring and the degree of correction

Flaps can be designed in many ways depending on the surgeon's preference and how pronounced the fold is, but this is described as not being the key step of epicanthoplasty ^[2]. Separating the tissue under the skin to fully release vertical tension and removing part of the orbicularis muscle are considered the main steps of the correction ^[2].

Techniques introduced in the past had problems such as visible scars, undercorrection, and recurrence ^[2]. Newer techniques have been refined to reduce tension on the wound by using shorter skin incisions and smaller flaps, and by minimizing or skipping the step of folding and securing the ligament at the inner corner of the eye (medial canthal ligament) ^[2]. In the systematic review as well, 6 studies tightened this ligament and 11 did not, showing that approaches differed ^[4].

These refinements are efforts to reduce scarring, but they do not mean there will be no scar. How a scar heals varies from person to person, depending on skin condition and the healing process.

Overcorrection and reversal surgery

Going too far with epicanthoplasty can lead to unwanted results, including overcorrection ^[3]. Surgery to restore overcorrected cases has become necessary, and research on restoration methods is being published ^[3].

Restoration methods are described as a field that is still developing ^[3]. Once the shape of the inner corner of the eye has been changed, returning it to how it was may not be easy, so it is important to decide carefully on the degree of correction at the first surgery.

What to ask during your consultation

How pronounced the epicanthal fold is, the distance between the eyes, and the shape of the double eyelid differ from person to person, so the same technique can produce different results. It is best to start by deciding together whether epicanthoplasty is needed at all ^[2].

• How pronounced your epicanthal fold is and whether epicanthoplasty is actually needed
• Which flap technique and incision length will be used
• The degree of correction and the risk of overcorrection
• Where the scar will be and how it will heal
• The plan if it is done together with double eyelid surgery