Telecanthus, or dystopia canthorum, refers to increased distance between the inner corners of the eyelids (medial canthi), while the

inter-pupillary distance Pupillary distance (PD) or interpupillary distance (IPD) is the distance measured in millimeters between the centers of the pupils of the eyes. This measurement is different from person to person and also depends on whether they are looking at ne ...

is normal. This is in contrast to

hypertelorism Hypertelorism is an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the orbits (eyes), or orbital hypertelorism. In this condition the distance between the inner eye corners as ...

, in which the distance between the whole eyes is increased. Telecanthus and hypertelorism are each associated with multiple congenital disorders. The distance between the inner corners of the eyelids is called the intercanthal distance. In most people, the intercanthal distance is equal to the width of each eye (the distance between the inner and outer corners of each eye). The average interpupillary distance is 60–62 millimeters (mm), which corresponds to an intercanthal distance of approximately 30–31 mm. ''Traumatic telecanthus'' refers to telecanthus resulting from traumatic injury to the nasal-

orbital Orbital may refer to: Sciences Chemistry and physics * Atomic orbital * Molecular orbital * Hybrid orbital Astronomy and space flight * Orbit ** Earth orbit Medicine and physiology * Orbit (anatomy), also known as the ''orbital bone'' * Orbito ...

ethmoid The ethmoid bone (; from grc, ἡθμός, hēthmós, sieve) is an unpaired bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a ...

(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 Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with child development, physical growth delays, mild to moderate ...

, fetal alcohol syndrome, cri du chat syndrome,

Klinefelter syndrome Klinefelter syndrome (KS), also known as 47,XXY, is an aneuploid genetic condition where a male has an additional copy of the X chromosome. The primary features are infertility and small, poorly functioning testicles. Usually, symptoms are s ...

Turner syndrome Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low h ...

, Ehlers–Danlos syndrome,

Waardenburg syndrome Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or one blue eye and one brown eye), a white forelock ...

often present with prominent epicanthal folds, and if these folds are nasal (as they most commonly are) they will cause telecanthus.

Etymology

''Telecanthus'' comes from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word (, "far") and the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

word ''

canthus The canthus (pl. canthi, palpebral commissures) is either corner of the eye where the upper and lower eyelids meet. More specifically, the inner and outer canthi are, respectively, the medial and lateral ends/angles of the palpebral fissure. T ...

'', meaning corner of the eyelid. ''Dystopia canthorum'' comes from the Greek - (-, “bad”) and (, “place”) and the Latin word ("of the canthi").

References

{{reflist Eye diseases Anatomy Greek words and phrases

Systemic associations

Etymology

See also

References