Telecanthus: Symptoms, Types, Causes and Treatment

Telecanthus is a distinctive facial feature that often brings patients to the attention of ophthalmologists, plastic surgeons, and geneticists. Characterized by an increased distance between the inner corners of the eyes (medial canthi), telecanthus can be an isolated finding or part of broader syndromic presentations. Understanding its symptoms, types, causes, and available treatments is crucial for accurate diagnosis and effective management. In this comprehensive article, we explore the critical aspects of telecanthus, making use of current research and clinical insights.

Symptoms of Telecanthus

Telecanthus presents primarily as a change in the appearance of the eyes, but its symptoms can extend beyond simple measurements. For many individuals, the difference is first noticed cosmetically, but it may be linked to functional or syndromic issues as well.

Symptom	Description	Associated Conditions	Source(s)
Increased ICD	Inner canthal distance >110% of normal	Blepharoptosis, trauma, syndromes	1, 5
Normal OOD	Outer canthal distance remains within normal limits	Distinguishes from hypertelorism	5
Epicanthal Fold	Fold of skin covering inner eye corner	More common in Asian eyelids	1
Facial Dysmorphism	Broad nasal bridge, syndactyly, other anomalies	STAR syndrome, MMCAT	2, 3

Table 1: Key Symptoms of Telecanthus

Increased Intercanthal Distance

The hallmark symptom of telecanthus is an abnormally wide distance between the medial canthi. This is measured as the inner canthal distance (ICD). Telecanthus is defined when the ICD exceeds 110% of the age- and sex-matched normal value 1. Notably, the outer canthal distance (OOD)—the space between the outer eye corners—remains normal, helping differentiate telecanthus from similar conditions 5.

Epicanthal Fold and Cosmetic Changes

A prominent epicanthal fold, particularly common in Asian populations, can make the eyes appear further apart. This sometimes leads to "pseudotelecanthus," where the ICD is normal but the fold creates an illusion of increased distance 1.

Syndromic Features

When telecanthus is part of a genetic syndrome, additional symptoms may be present, such as:

• Microcornea and myopia (in MMCAT syndrome) 2
• Facial dysmorphism, syndactyly, and anogenital or renal anomalies (in STAR syndrome) 3
• Ptosis (drooping eyelids), especially when associated with trauma or congenital anomalies 1

Functional and Psychological Impact

Although primarily a cosmetic issue, telecanthus may affect eye function (e.g., tear drainage) and can have psychosocial effects due to altered facial appearance. In trauma cases, it may be accompanied by other injuries that impact vision or eye movement 4, 7.

Types of Telecanthus

Telecanthus is not a one-size-fits-all condition. It can be classified based on its severity, underlying cause, and relationship to other craniofacial anomalies. Recognizing the type is essential for planning effective management.

Type	Definition/Criteria	Key Feature(s)	Source(s)
Primary	Soft tissue anomaly, normal bony orbits	Isolated medial canthi separation	5
Secondary	Bony orbital involvement	Increased interorbital distance	5
Pseudotelecanthus	Normal ICD, wide skin bridge (epicanthal fold)	Epicanthal fold illusion	1
Severity-based	Mild, moderate, severe (by ICD increase)	Guides surgical options	1

Table 2: Types and Classifications of Telecanthus

Primary vs. Secondary Telecanthus

• Primary telecanthus is due to abnormal development or placement of the soft tissues around the eyes, with the bony orbits themselves normally positioned. The medial canthi are separated, but the interorbital distance (space between the bony orbits) is unchanged 5.
• Secondary telecanthus arises when there is true widening of the bony orbits, resulting in both increased intercanthal and interorbital distances. This form often follows significant craniofacial trauma or is associated with congenital craniosynostosis syndromes 5.

Pseudotelecanthus

This term describes the illusion of increased separation between the eyes caused by an exaggerated epicanthal fold, even though the ICD is within normal limits. It is particularly notable in some ethnic populations and does not require surgical correction unless for cosmetic reasons 1.

Severity-Based Classification

Recent advances suggest classifying telecanthus by the degree of ICD increase:

• Mild: Slightly above normal ICD
• Moderate: Noticeable but not extreme increase
• Severe: Marked separation, often with associated structural problems

This classification helps guide surgical intervention choices, as some procedures are better suited for mild-to-moderate cases, while severe cases may require more complex reconstruction 1.

Causes of Telecanthus

Understanding why telecanthus occurs is essential for both prevention (when possible) and effective treatment. Causes can be broadly divided into congenital, acquired, and syndromic categories.

Cause	Description	Example Conditions/Situations	Source(s)
Congenital	Present at birth, often genetic	STAR, MMCAT syndromes	2, 3, 5
Traumatic	Due to injury, especially midfacial fractures	Naso-orbito-ethmoidal fractures	4, 6, 7, 8
Soft Tissue Abnormality	Maldevelopment of canthal tendons	Isolated primary telecanthus	5
Bony Abnormality	Unusual development of facial/cranial bones	Hypertelorism (secondary telecanthus)	5
Iatrogenic	Post-surgical or tumor resection	Medial canthal tendon disruption	9, 10

Table 3: Main Causes of Telecanthus

Congenital and Genetic Causes

• Syndromic Associations: Telecanthus can be a feature of rare genetic syndromes such as MMCAT (microcornea, myopic chorioretinal atrophy, and telecanthus), caused by mutations in the ADAMTS18 gene 2, or STAR syndrome (syndactyly, telecanthus, anogenital, and renal malformations) due to FAM58A mutations 3. These are often inherited and may present with other systemic findings.
• Isolated Congenital Telecanthus: Some cases occur without broader syndromic involvement, likely due to isolated developmental anomalies in the medial canthal region 5.

Traumatic Causes

• Midfacial Trauma: The most common acquired cause is trauma, especially fractures involving the naso-orbito-ethmoidal (NOE) complex. These injuries can disrupt the medial canthal tendon (MCT), leading to lateral displacement of the canthus 4, 6, 7, 8.
• Delayed Repair Complications: Late or inadequate repair of NOE fractures can result in persistent or worsening telecanthus due to scarring and secondary deformity 7, 8.

Other Acquired Causes

• Iatrogenic: Surgical procedures, tumor resections, or craniofacial exposures that disrupt the MCT or surrounding structures can lead to telecanthus 9, 10.

Distinguishing from Ocular Hypertelorism

Ocular hypertelorism, in contrast, is due to bony orbit separation, not just soft tissue displacement. The distinction is essential for diagnosis and management 5.

Treatment of Telecanthus

Effective treatment for telecanthus depends on the underlying cause, severity, and whether it is part of a syndrome or isolated. Advances in surgical techniques have improved both functional and cosmetic outcomes.

Treatment Modality	Main Features/Techniques	Best For	Source(s)
Medial Canthopexy	Reattaches medial canthal tendon to bone	Traumatic cases	4, 7, 8, 9, 10
Transnasal Wiring	Gold standard, wires pass through nasal bone	Complex NOE fractures	7, 10
Flowers' split V-W plasty	Combines skin and tendon repair	Mild/moderate congenital	1
Microanchor Devices	Titanium anchors for stable fixation	Unilateral/bilateral acquired	9
Y-V Epicanthoplasty	Minimizes scarring, suitable for cosmetic correction	Congenital, neoplastic	10
Early vs Delayed Repair	Early intervention yields best results	Acute trauma cases	4, 8

Table 4: Treatment Modalities for Telecanthus

Medial Canthopexy

This surgical technique is central to most telecanthus repairs, especially in trauma. It involves reattaching the medial canthal tendon to its proper position on the bone. Techniques include:

• Transnasal Wiring: Considered the gold standard, especially in NOE fractures, but technically demanding 7, 10.
• Microanchor Devices: Offer a less invasive, reliable alternative, especially useful in ipsilateral (one-sided) cases and for minimizing incisions 9.

Skin and Tendon Repair Techniques

• Flowers' Split V-W Plasty: This method combines plasty of the skin and shortening of the medial canthal tendon, particularly effective in mild to moderate congenital telecanthus, with minimal scarring and low recurrence rates 1.
• Y-V Epicanthoplasty Incision: This approach allows for better access and minimal visible scarring while repositioning the MCT, suitable for both traumatic and congenital cases. It is especially valued for its cosmetic outcomes 10.

Timing of Surgery

• Early vs Delayed Repair: Early intervention, ideally during the initial trauma surgery, provides the best functional and cosmetic outcomes. Delayed repairs are more complex due to scarring and anatomical distortion, with higher rates of complications 4, 7, 8.

Special Considerations

• Severity Matters: Severe telecanthus may require more complex, multi-stage reconstructions and may have higher risks of incomplete correction or recurrence 1.
• Syndromic Cases: When telecanthus is part of a broader syndrome, treatment may be tailored to address both the cosmetic aspect and associated anomalies, often involving a multidisciplinary team 2, 3.

Outcomes and Complications

• Most modern techniques achieve stable correction and restoration of the normal intercanthal distance, with good cosmetic results. However, recurrence, scarring, and in rare cases, functional complications (such as tear drainage problems) may occur 1, 7, 9, 10.

Conclusion

Telecanthus is a multifaceted condition that can arise from a variety of congenital, traumatic, and acquired causes. While often presenting as an isolated cosmetic concern, it may signal underlying syndromes or significant injuries. Advances in surgical techniques, particularly those focusing on early intervention and minimally invasive approaches, have greatly enhanced patient outcomes. Recognizing the type and cause of telecanthus is essential for selecting the optimal treatment plan.

Main Points:

• Telecanthus is defined by increased distance between the medial canthi, with normal outer canthal distance.
• It can be primary (soft tissue), secondary (bony), or pseudotelecanthus (illusion due to epicanthal fold).
• Causes include congenital syndromes, trauma (especially NOE fractures), and surgical disruption.
• Treatments focus on surgical repositioning of the medial canthal tendon, with various techniques tailored to cause and severity.
• Early intervention offers the best results, while innovative approaches minimize scarring and improve fixation.
• Multidisciplinary management is vital for syndromic cases or complex trauma.

Understanding and addressing telecanthus requires careful measurement, thorough clinical evaluation, and individualized treatment planning for optimal functional and cosmetic restoration.