Introduction 

Telecanthus is a rare palpebral (eyelid) anomaly that causes an increased distance (lateral displacement) between the medial canthi (inner corners of the eyelids), also called wide eyes. It is caused by a variety of factors, predominantly being a congenital condition often linked to genetic disorders. It is often associated with hypertelorism (an increased distance between the eyes), and is also known as dystopia canthorum. It can be unilateral or bilateral (affecting one or both eyes, respectively). Traumatic facial injuries can also cause telecanthus. While telecanthus doesn't usually cause any eye pain or vision problems, its association with other syndromes can lead to low vision, myopia (nearsightedness) and hyperopia (farsightedness). The condition is caused by the abnormal lengthening or insertion of the medial canthal tendons.¹ Telecanthus is the most frequent ocular finding in foetal alcohol syndrome and is also associated with Waardenburg syndrome and blepharophimosis syndrome (characterised by narrowed eye openings drooping eyelids).²

What are the causes of Telecanthus?

• Trauma (e.g., naso-frontoethmoidal fractures)
• Orbital tumours
• Ethnic variation

Epicanthus

Epicanthus refers to a fold of skin that extends from the upper eyelid across the inner corner (canthus) of the eye. It is usually bilateral and is often inherited as an autosomal dominant trait. It is caused by immature facial bones and excess skin. This common congenital variation is usually self-correcting as the root of the nose and face develop and grow. Ptosis (the drooping of the eyelids) may be associated with epicanthus. It may also be found with Ehlers-Danlos syndrome.³

Types of epicanthus:

1. Epicanthus supraciliaris: A vertical fold of skin that extends from just below the brow to an area over the infraorbital rim, obscuring the caruncle³
2. Epicanthus inversus: Similar to epicanthus tarsalis but primarily involves the lower lid. It is associated with blepharophimosis and may cause skin distress in the lateral periorbital region.⁸ This type is seen as a part of Blepharophimosis, Ptosis-Epicanthus Syndromes (BPES)⁴
3. Epicanthus tarsalis: A condition where a fold begins laterally and extends over the entire eyelid, ending in the medial canthus

What are the symptoms of epicanthus?

Individuals with epicanthus may experience blurred vision if the skin fold obstructs the visual axis. They may also experience constant friction from the skin fold. In severe cases epicanthus can lead to amblyopia, or lazy eye, affecting vision development in children.⁴

What are the causes of epicanthus?

The primary cause of epicanthus is the lack of a vertical axis within the medial canthal region. The condition may be unilateral or bilateral and is most prominent along the upper eyelid.⁴

Combined presentation: causes and associations

1. Normal variant 

Prominent epicanthal folds can cause pseudoesotropia, where eyes appear crossed due to the epicanthal folds themselves, rather than true misalignment. These folds can be caused by excessive development of the skin across the bridge of the nose. Children with prominent epicanthal folds may appear esotropic, resulting in pseudostrabismus.³

2. Combined associations

• Waardenburg syndrome: Sensorineural deafness, pigmentation abnormalities 
• Down's syndrome: Epicanthal folds, hypotonia (reduced muscle tone), intellectual disability
• Turner syndrome: Epicanthal folds, low-set ears 
• Noonan syndrome: Epicanthal folds, hypertelorism, congenital heart defects
• Cri-du-chat syndrome: Telecanthus, epicanthal folds, high pitched microcephaly, intellectual disability

Blepharophimosis, Ptosis and Epicanthus Inversus Syndrome (BPES) 

BPES is a rare genetic disorder primarily affecting eyelid development, resulting in a distinct facial appearance. Some individuals with BPES experience significant ptosis and visual impairment.⁴

• Blepharophimosis: Narrowing of the horizontal aperture of eyelids
• Ptosis: Drooping of the eyelid causing a narrowing of the palpebral fissure
• Telecanthus: Lateral displacement of inner canthi
• Epicanthus Inversus: Narrowing of the eye opening and droopy eyelids

Injuries or conditions developing Telecanthus:

• Basal cell carcinomas
• Naso-orbital ethmoid fractures
• Squamous cell carcinomas

Diagnosis 

Epicanthus can be diagnosed through physical examination by observing the fold of skin covering the inner corner of the eye. Medical history and family history play a very important role in the diagnosis. Ophthalmological evaluation, including careful inspection of the eyelids and checking for skin folds that run from the upper eyelid across the inner corner of the eye, is crucial.

Treatment 

Epicanthus is primarily corrected surgically, using techniques aimed at modifying the position and shape of the skin fold to improve the aesthetic appearance of the eyelids. The goal is to adjust the starting and end points of skin folds to increase palpebral fissure length and reduce intercanthal distance. Various surgical techniques for epicanthus are available in clinical practice, such as flap transposition and flap advancement.¹⁰

Surgical procedures for telecanthus 

Telecanthus often requires cosmetic correction. Numerous surgical procedures have been attempted to treat telecanthus, including transnasal wiring, screw fixation and medial canthoplasty.⁵ Medial canthal tendon shortening and repositioning are also common approaches.⁹

FAQs

How common is Telecanthus?

Telecanthus usually occurs along with other genetic syndromes.

Is Telecanthus a congenital disorder?

Yes, telecanthus is often a congenital condition, meaning it is present at birth and is usually a genetic disorder. It can also be acquired by trauma.

Does telecanthus affect vision?

No, telecanthus itself does not impair vision; it mainly affects appearance. However, telecanthus associated with other eye abnormalities may lead to visual problems. Children may feel uncomfortable due to their appearance.

How can the severity of epicanthus be measured?

The severity of epicanthus can be graded based on the degree of caruncle obscuration; severe cases involve complete covering of the caruncle.¹¹

What causes telecanthus?

During embryonic development, the inner corners of eyes fail to come sufficiently close together, and the frontonasal prominence does not form properly, giving the appearance of the eyes being farther apart.¹

What is traumatic telecanthus?

Traumatic telecanthus is due to fracture of the nasoethmoid bones and other facial injuries due to medial canthal lacerations.

Summary 

Telecanthus is characterised by an increased distance between the inner corners of the eye (medial canthi). It results from an unusual insertion or length of the medial canthi. Frequently, it is seen in Blepharophimosis, Ptosis, Epicanthus Inversus Syndrome (BPES). Telecanthus is typically considered abnormal when the inner canthal distance exceeds 30-35mm in adults. It could also be due to trauma or surgery to the medial canthus. Epicanthus is a skin fold that covers the inner corners of the eyelid. The condition is self correcting with the growth of the root of the nose and face.