Heterokromi

Heterokromi, also known as heterochromia, is a condition in which the irises differ in color, either between the two eyes or within a single iris. It can be noticeable or subtle, and may be present from birth or develop later. In humans it is usually benign, while in animals such as dogs and cats it can be a normal breed trait.

There are three commonly described forms: complete heterochromia, where each iris is a different color; sectoral (or partial) heterochromia, where part of one iris has a different color; and central heterochromia, where the inner circle around the pupil differs in color from the rest of the iris.

Causes include genetic factors that affect pigment distribution in the iris. Congenital heterochromia is typically harmless and inherited. Acquired heterochromia can result from eye injury or inflammation, or from systemic diseases. Medications used for glaucoma, such as prostaglandin analogs, can alter iris coloration. Some conditions, including Waardenburg syndrome or Horner’s syndrome, may feature heterochromia as part of their presentation. In some cases, chimerism or mosaicism can also produce asymmetric iris coloration.

Diagnosis is generally clinical, based on examination and history. If heterochromia appears suddenly or is accompanied by vision changes, pain, or a red eye, medical evaluation is advised to identify any underlying condition. There is typically no treatment needed for benign congenital heterochromia; management focuses on any associated ocular or systemic issues if present.