Epicanthal Folds

What epicanthal folds are

The epicanthus is a vertical fold of skin running from the upper eyelid down toward the inner corner of the eye (the medial canthus). It partly or fully covers the small pink tissue at the inner corner (the caruncle). Doctors describe four types:

Why epicanthal folds occur

Normal variation

Epicanthal folds are a common inherited facial feature, found in a large proportion of people of East Asian, Central Asian, Southeast Asian, and Indigenous American ancestry, and in some people of other ancestries. They are linked to how the eyelid skin and underlying tissue attach and to a lower, wider nasal bridge.

Infancy

Almost all babies have a flat nasal bridge, so many have epicanthal folds that become less obvious as the nose grows. They often fade noticeably by around age 3 to 5 in children whose families do not have the trait.

Genetic and developmental conditions

Epicanthal folds are one of many features doctors look for when assessing a child for a syndrome. On their own they never establish a diagnosis. Conditions in which they are common include:

• Down syndrome (trisomy 21): upward-slanting eyes, epicanthal folds, a flat facial profile, small ears, a single palm crease and low muscle tone.
• Fetal alcohol syndrome: short eye openings, a smooth philtrum (the groove above the lip), a thin upper lip, small head size and learning difficulties.
• Turner syndrome: girls with short stature, a webbed neck and drooping eyelids.
• Noonan syndrome: wide-spaced eyes, droopy lids, short stature and heart defects.
• Blepharophimosis-ptosis-epicanthus inversus syndrome (BPES): narrow eye openings, drooping lids and reverse folds.
• Williams syndrome, Zellweger syndrome and chromosomal disorders such as trisomy 18.

Epicanthal folds and "crossed eyes"

Wide epicanthal folds cover more of the white of the eye on the nose side, especially when a baby looks to the side. This makes the eyes look turned inward even when they are perfectly aligned. This is called pseudostrabismus and is one of the most common reasons parents bring babies to an eye doctor.

A simple check doctors use is the light reflex test: shining a light at the eyes and seeing whether the reflection sits in the same spot on each pupil. In pseudostrabismus it does. In true strabismus, it does not. True strabismus needs treatment, because an eye that turns can develop lazy eye (amblyopia).

Babies' eyes can wander occasionally in the first 3 to 4 months. A turn that persists after that, or is constant at any age, should be checked.

How doctors assess epicanthal folds

For an otherwise healthy child with normal development, a quick examination is all that is needed. A pediatrician or geneticist will look further if the folds come with:

• other facial differences
• low muscle tone, feeding difficulties or heart murmurs
• slow growth or developmental delay
• a family or pregnancy history that raises concern

Tests may include an eye exam, a heart scan, chromosome analysis or other genetic testing.

Treatment

Epicanthal folds themselves need no treatment and do not affect vision. Where an underlying condition is present, care focuses on that condition.

Some adults choose cosmetic eyelid surgery (medial epicanthoplasty) to change the shape of the inner eye corner. This is a personal choice, not a medical need, and carries risks of visible scarring. In BPES, surgery is sometimes done in childhood to lift drooping lids and protect vision.

Frequently asked questions

What are epicanthal folds?

They are folds of upper eyelid skin that cover the inner corner of the eye. They are a normal inherited feature in many populations, especially people of East Asian ancestry, and are common in all babies because the bridge of the nose is still flat.

Do epicanthal folds mean Down syndrome?

No. Most people with epicanthal folds do not have Down syndrome or any other condition. They are common in people with Down syndrome, but doctors diagnose syndromes from a combination of features and genetic testing, never from eye shape alone.

Do babies grow out of epicanthal folds?

Often, yes. In babies from families without the trait, the folds usually become less noticeable as the nasal bridge grows during the first few years of life. In families where the trait is inherited, they persist.

Can epicanthal folds make eyes look crossed?

Yes. The folds hide the white of the eye near the nose, making the eyes look turned inward. This is called pseudostrabismus. An eye doctor can confirm that the eyes are aligned with a simple light reflex test.