What causes sectoral heterochromia?

Sectoral heterochromia is a rare eye condition in which a person has two different colored irises. This condition occurs when there is a difference in the amount of melanin in the different sectors of the iris. Melanin is the pigment that gives the iris its color.

The most common cause of sectoral heterochromia is a genetic mutation. This mutation can occur in either the OCA2 or SLC24A4 gene. The OCA2 gene is responsible for producing a protein that helps to transport melanin to the iris. The SLC24A4 gene is responsible for producing a protein that helps to regulate the amount of melanin in the iris. When either of these genes is mutated, it can lead to a difference in the amount of melanin in the different sectors of the iris, resulting in sectoral heterochromia.

Other causes of sectoral heterochromia include:

* Trauma: An injury to the eye can cause damage to the iris, leading to a difference in the amount of melanin in the different sectors of the iris.

* Infections: Infections of the eye, such as iritis, can also cause damage to the iris, leading to sectoral heterochromia.

* Certain medications: Some medications, such as prostaglandin analogs, can cause changes in the amount of melanin in the iris, leading to sectoral heterochromia.

* Glaucoma: People with glaucoma are more likely to develop sectoral heterochromia. This is because glaucoma can damage the optic nerve, which can lead to changes in the amount of melanin in the iris.