An epicanthal fold is a crescent-shaped fold of skin on the upper eyelid that covers the inner corner of the eye, known as the medial canthus. This is the area where the upper and lower eyelids meet near the nose. The presence of this fold can make the nasal bridge (the area between the eyes) appear wider and can obscure some of the white part of the eye (the sclera) on the inner side, which can sometimes create the illusion that the eyes are crossed.

To understand why this feature appears, it is helpful to use an analogy.

• Think of the skin over the bridge of your nose and around your eyes as a small, smooth tent canvas.
• The underlying bone and cartilage of your nasal bridge act as the central “tent pole.”
• In many newborns of all ethnicities, this tent pole is still very low and flat because the nasal bridge has not yet fully developed and grown taller. Because the pole is not high, the canvas has some extra slack, and it naturally drapes and creates a small fold at the inner corner of each eye.
• As many children of non-Asian descent grow, their nasal bridge becomes higher and more prominent. This “lifts” the tent pole, pulling the canvas taut and causing the epicanthal fold to disappear, usually by school age.
• In individuals of East Asian descent, a relatively lower nasal bridge is a normal adult facial feature, so the epicanthal fold often remains as a permanent and characteristic trait.

In my experience, many parents first notice epicanthal folds as a skin fold near the inner corner of the eye in infants often mistaking it for an eye alignment issue like strabismus.

Epicanthal fold is not caused by a disease or a genetic mutation in the typical sense. It is simply a result of the anatomical structure of a person’s face, primarily the shape and height of the nasal bridge in relation to the eyelids.

It is a normal variation in human anatomy, just like having attached or detached earlobes, a widow’s peak, or dimples. The underlying muscles and structures of the eye are completely normal. The presence of the fold is determined by the development of the facial bones and soft tissues, which is guided by a person’s genetic and ethnic background.

In my experience, the presence of these folds alone isn’t always concerning but when accompanied by other physical features, it may prompt genetic evaluation.

An epicanthal fold is a congenital feature, meaning it is present at birth. It is not something you can “get” or develop later in life (an acquired fold in an adult could be a sign of another issue).

• It is a normal developmental stage: Virtually all human fetuses have prominent epicanthal folds early in gestation. In many infants, especially those of Caucasian or African descent, these folds naturally disappear as the face, and particularly the bridge of the nose, grows and develops during the first few years of life.
• It is a normal ethnic feature: Prominent epicanthal folds that persist into adulthood are a normal and characteristic facial feature for the majority of people of East Asian and Central Asian descent. They are also common in a variety of other populations around the world.
• It is not contagious and is not caused by any action or inaction of the parents during pregnancy.

In my experience, epicanthal folds are often inherited or seen during infancy and may fade with facial growth especially as the nasal bridge develops.

An isolated epicanthal fold is a physical sign, not a medical problem, and it has no symptoms. It does not cause pain, discomfort, or any problems with vision.

The primary “symptom” or concern that brings this feature to medical attention is the illusion of crossed eyes, a condition known as pseudostrabismus.

• Because the fold of skin covers the inner white part of the eye, less white is visible on the side near the nose compared to the side near the ear.
• This can trick an observer’s brain into thinking the eye is turned inward, especially when the baby is looking to the side.
• Pseudostrabismus is the most common reason that infants are referred to a pediatric ophthalmologist for an evaluation of “crossed eyes.”

Parents often report that their child appears cross-eyed, but the visual alignment is actually normal, it’s the fold that creates an optical illusion.

The diagnosis of an epicanthal fold is made instantly and simply by visual inspection. A parent, pediatrician, or ophthalmologist can see the fold of skin. No tests are needed to identify the fold itself.

The goal of a medical evaluation is not to diagnose the fold, but to do two very important things:

1. Differentiate pseudostrabismus from true strabismus.
2. Assess the child for any other physical or developmental signs that might suggest an underlying genetic syndrome.

The Eye Examination

A pediatrician or pediatric ophthalmologist can easily determine if a child’s eyes are straight. The simplest method is the corneal light reflex test.

• The doctor shines a small light toward the child’s eyes.
• They observe where the reflection of the light appears on the child’s corneas.
• If the eyes are straight, the reflection will be in the exact same spot in the center of the pupil of each eye.
• If one eye is truly turned in or out, the reflection will be off-center in that eye. This confirms true strabismus, which requires treatment, and rules out pseudostrabismus.

When is Epicanthal Fold a Sign of a Medical Condition?

It is crucial to understand that an isolated epicanthal fold in an otherwise healthy, developing child is a normal finding.

A doctor only becomes concerned that an epicanthal fold may be part of a larger syndrome if it is present in combination with multiple other significant features. These can include:

• Very distinct facial features beyond just the epicanthal folds.
• A single crease across the palm of the hand.
• Severe hypotonia (very low muscle tone or “floppiness”).
• Congenital heart defects.
• Significant global developmental delays.

If this constellation of signs is present, the epicanthal fold is considered one clue among many that points to a possible underlying genetic or chromosomal disorder. In this situation, a doctor would recommend a consultation with a clinical geneticist and further testing to look for conditions such as Down syndrome (Trisomy 21), fetal alcohol syndrome, or other rare genetic syndromes where epicanthal folds are a common feature.

Clinically, I diagnose epicanthal folds through physical examination, often as part of a routine pediatric check-up or developmental assessment.

For an isolated epicanthal fold that is a normal ethnic or developmental feature, the recommended and correct course of action is no treatment at all.

Because it is a harmless anatomical variation and not a disease, there is no medical reason to intervene.

• Natural Course: As mentioned, in most infants of non-Asian heritage, the folds will naturally become less prominent and often disappear completely as the child’s nasal bridge grows taller between the ages of 3 and 5.
• No Medical Treatment: There are no creams, exercises, or medications that can or should be used to alter this normal feature.

Cosmetic Surgery (Epicanthoplasty)

In some cultures, particularly in East Asia, a plastic surgery procedure called an epicanthoplasty is available to reduce or remove the epicanthal fold. It is important to understand that:

• This is a purely cosmetic procedure.
• It is performed on adults who wish to change the appearance of their eyes, often to create a “double eyelid.”
• It has no medical benefit and is not performed on children to “correct” what is considered a normal anatomical feature.

Treating Associated Conditions

If the eye exam reveals that a child has true strabismus or another vision problem like a significant refractive error, that is the condition that will be treated. Treatment might involve glasses, eye patching, or eye muscle surgery. This treatment is for the underlying vision problem, not for the epicanthal fold itself.

I’ve found that most cases in infants resolve naturally as the face matures, no treatment is needed unless there’s an underlying condition or cosmetic concern later in life.

The discovery of epicanthal folds on a baby’s face often causes unnecessary worry for new parents. It is essential to be reassured that these small folds of skin at the inner corner of the eyes are, in the vast majority of cases, a completely normal and harmless finding. They are a common feature of infancy for babies of all races that usually fade with time, and they are a normal, lifelong characteristic for many people of Asian descent. While they can create the illusion of crossed eyes, a simple eye exam can provide reassurance that the eyes are aligned correctly. In my experience, once families understand that epicanthal folds are often normal and self-limited, their concerns ease especially if pseudostrabismus is explained.

American Academy of Ophthalmology (AAO). (2023). What is Pseudostrabismus? Retrieved from https://www.aao.org/eye-health/diseases/what-is-pseudostrabismus

American Association for Pediatric Ophthalmology and Strabismus (AAPOS). (n.d.). Epicanthal Folds. Retrieved from https://aapos.org/glossary/epicanthal-folds

National Institutes of Health, National Human Genome Research Institute. (n.d.). Epicanthal Fold. Retrieved from https://elementsofmorphology.nih.gov/index.cgi?tid=d365a6e279a0b411