What is "telecanthus"

n. Increased distance between the medial canthus of the eyes, while the interpupillary distance is normal.

Telecanthus (from the Greek word "tele" meaning far, and the Latin word canthus, meaning either corner of the eye, where the eyelids meet) refers to increased distance between the medial canthi of the eyes, while the inter-pupillary distance is normal. This is in contrast to hypertelorism, where the inter-pupillary distance is increased.

The distance between the inner corner of the left eye and the inner corner of the right eye, is called intercanthal distance. In most people, the intercanthal distance is equal to the distance between the inner corner and the outer corner of each eye, that is, the width of the eye. The average interpupillary distance is 60–62 millimeters (mm), which corresponds to an intercanthal distance of approximately 30–31 mm. The situation, where intercanthal distance is intensely bigger than the width of the eye, is called telecanthus (tele= Greek τηλε = far, and Greek ακανθα = thorn). This can be an ethnic index or an indication for hypertelorism or hypotelorism, if it is combined with abnormal relation to the interpupillary distance (A D STEAS).

Traumatic Telecanthus refers to telcanthus resulting from traumatic injury to the nasal-orbital-ethmoid (NOE) complex. The diagnosis of traumatic telecanthus requires a measurement in excess of those normative values. The pathology can be either unilateral or bilateral, with the former more difficult to measure.

Systemic Associations

Telecanthus is often associated with many congenital disorders. Congenital disorders such as down syndrome, fetal alcohol syndrome, Cri du Chat syndrome, Klinefelter syndrome, turner syndrome, Ehlers-Danlos syndrome often present with prominent epicanthal fold and if these folds are nasal (most commonly are) they will cause telecanthus.

Fig of the used terms