Canthus

CuttingLateralCanthus

Canthus is the anatomical term referring to the area where the upper and lower eyelids meet. There are two canthi for each eye: the medial canthus, which is near the nose, and the lateral canthus, which is on the side away from the nose. These structures are significant in both medical and cosmetic fields, playing a crucial role in the overall health and appearance of the eye.

Anatomy

The canthus is made up of skin and underlying connective tissue that supports the junctions of the eyelids. The medial canthus contains the lacrimal caruncle, a small, pink, globular nodule at the inner corner of the eye, which is part of the tear drainage system. This system is crucial for eye health, as it helps to drain tears into the nasolacrimal duct, keeping the eye moist and free from irritants.

The lateral canthus is structurally more rigid and is where the eyelids are tethered to the orbit by the lateral canthal tendon. This structure provides stability to the outer edge of the eyelids and is often a focus in cosmetic and reconstructive eyelid surgery.

Clinical Significance

The canthi are involved in several medical conditions and surgical procedures. Canthal dystopia, where the canthi are not aligned properly, can lead to problems with tear drainage and eye closure. This condition may be congenital or acquired through trauma or disease. Canthoplasty, a surgical procedure aimed at reconstructing or altering the canthus, is often performed for both functional and aesthetic reasons. Conditions such as entropion, where the eyelid turns inward, or ectropion, where the eyelid turns outward, may also involve surgical attention to the canthal areas to correct eyelid malposition and improve patient comfort and eye health.

Infections and Inflammations

Infections such as dacryocystitis, an infection of the lacrimal sac, often present with swelling and tenderness at the medial canthus. Inflammatory conditions like blepharitis, inflammation of the eyelid margins, can also affect the canthi, leading to discomfort and redness.

Cosmetic Considerations

In the field of cosmetic surgery, the appearance of the canthi is a common concern. Procedures such as blepharoplasty (eyelid surgery) may involve modifications to the canthal area to achieve a desired aesthetic outcome. The angle and tension of the canthi can significantly affect the perceived age and mood of the face, making this an area of particular interest for cosmetic interventions.

Conclusion

The canthi play a critical role in the function and appearance of the eyes. Understanding the anatomy and clinical significance of the canthus is essential for diagnosing and treating conditions that affect the eyelids and the surrounding areas. As such, the canthus is a key focus in both ophthalmology and cosmetic surgery.