Heterochromia iridum

Heterochromia iridum
Specialty	Ophthalmology

In anatomy, heterochromia refers to a difference in coloration, usually of the irises but also of hair or skin.

Heterochromia (also known as a heterochromia iridis or heterochromia iridium) is an ocular condition in which one iris is a different color from the other (complete heterochromia), or where part of one iris is a different color from the remainder (partial heterochromia or sectoral heterochromia). It is a result of the relative excess or lack of pigment within an iris or part of an iris, which may be inherited or acquired by disease or injury.

An example of sectoral heterochromia iridis. The subject has a blue iris with a brown section.

Eye color, specifically the color of the irises, is determined primarily by the concentration and distribution of melanin pigment within the iris tissues [1]. Consequently, anything affecting those factors may result in a difference of color being observed.

An excess of pigmentation is usually associated with hyperplasia of the iris tissues whereas a lack of pigmentation is associated with hypoplasia. Although seen in humans, heterochromia in which one iris differs in color from the other iris is more frequently observed in non-human species such as cats (for example, Japanese Bobtails; white, shorthaired cats can be "odd-eyed" with one copper or orange eye and one blue eye, and the Turkish Angora), dogs (for example, Siberian Huskies as well as Australian Shepherds, Border Collies, and other breeds with merle coats), horses (so-called "walled-eyed" horses have one brown and one white eye), and even water buffalo. Partial or sectoral heterochromia is much less common than complete heterochromia and is typically found in autosomally inherited disorders such as Hirschsprung's disease and Waardenburg's syndrome.

Blue merle Border Collie with blue-and-brown eye.

Classification based on etiology

Although a distinction is frequently made between heterochromia that affects an eye completely or only partially, it is often classified as either congenital or acquired with mention as to whether the affected iris or portion of the iris is darker or lighter.

Congenital heterochromia

Heterochromia that is congenital is usually inherited as an autosomal dominant trait.

Abnormal iris darker

• Lisch nodules - iris hamartomas seen in neurofibromatosis.
• Ocular melanosis - a condition characterized by increased pigmentation of the uveal tract, episclera, and anterior chamber angle.
• Pigment dispersion syndrome - a condition characterized by loss of pigmentation from the posterior iris surface which is disseminated intraocularly and deposited on various intraocular structures, including the anterior surface of the iris.
• Sturge-Weber syndrome - a syndrome characterized by a port-wine stain nevus in the distribution of the trigeminal nerve, homolateral meningeal angioma with intracranial calcification and neurologic signs, and angioma of the choroid, often with secondary glaucoma[2].

Abnormal iris lighter

• Simple heterochromia - a rare condition characterized by the absence of other ocular or systemic problems. The lighter eye is typically regarding as the affected eye as it usually shows iris hypoplasia. It may affect an iris completely or only partially.
• Congenital Horner's syndrome - sometimes inherited, although usually acquired
• Waardenburg's syndrome - a syndrome in which heterochromia presents as a bilateral iris hypochromia in some cases. A Japanese review of 11 albino children with the disorder found that all had sectoral/partial heterochromia.
• Piebaldism - similar to Waardenburg's syndrome, a rare disorder of melanocyte development characterized by a white forelock and multiple symmetrical hypopigmented or depigmented macules.
• Hirschsprung's disease - a bowel disorder associated with heterochromia in the form of a sector hypochromia. The affected sectors have been shown to have reduced numbers of melanocytes and decreased stromal pigmentation.

Acquired heterochromia

Heterochromia that is acquired is usually due to injury, inflammation, the use of certain eyedrops, or tumors.

Abnormal iris darker

• Deposition of material
  • Siderosis - iron deposition within ocular tissues due to a penetrating injury and a retained iron-containing, intraocular foreign body.
  • Hemosiderosis - long standing hyphema (blood in the anterior chamber) following blunt trauma to the eye may lead to iron deposition from blood products
• Use of certain eyedrops - prostaglandin analogues (latanoprost, isopropyl unoprostone, travoprost, and bimatoprost) are used topically to lower intraocular pressure in glaucoma patients. A concentric heterochromia has developed in some patients applying these drugs. The stroma around the iris sphincter muscle becomes darker than the peripheral stroma. A stimulation of melanin synthesis within iris melanocytes has been postulated.
• Neoplasm - Nevi and melanomatous tumors.

Abnormal iris lighter

• Fuchs' heterochromic iridocyclitis - a condition characterized by a low grade, a symptomatic uveitis in which the iris in the affected eye becomes hypochromic and has a washed-out, somewhat moth eaten appearance. The heterochromia can be very subtle, especially in patients with lighter colored irides. It is often most easily seen in daylight. The prevalence of heterochromia associated with Fuch's has been estimated in various studies with results suggesting that there is more difficulty recognizing iris color changes in dark-eyed individuals.
• Acquired Horner's syndrome - usually acquired, as in neuroblastoma, although sometimes inherited.
• Neoplasm - Melanomas can also be very lightly pigmented, and a lighter colored iris may be a rare manifestation of metastatic disease to the eye.

Examples

Heterochromia can occur in several species of animals, including cats.

File:Bi-eyehusky.JPG

A Siberian husky with heterochromia.

Celebrities

• Dan Aykroyd has one blue eye and one brown eye. (see photo)
• Gracie Allen, was described as having one green eye and one blue eye in her widower, George Burns' autobiography. She stopped making movies once they became colourized.
• David Bowie naturally born with two blue eyes, but after experiencing a childhood injury now has a permanently dilated left eye that appears brown and green depending on the light.
• Kate Bosworth has sectoral heterochromia; two blue eyes with a hazel section at the bottom of her right eye (see photo #1 and photo #2).
• Jessica Cauffiel has sectoral heterochromia, two green eyes with brown pigmentation on left eye (see photo).
• Mila Kunis has a left green eye and right blue eye (see photo).
• Jane Seymour has a left green eye and right brown eye (see photo)

Fictional characters

• Vile of the Mega Man X series has one red eye and one blue/green eye.
• Kazuya Mishima of the Tekken series has a left red eye due to the Devil Gene.
• M. Woland (Satan) of The Master and Margarita by Mikhail Bulgakov has one eye green, the other black, as a foreshadow of his bringing chaos to Moscow.
• Conrad Nomikos, protagonist of This Immortal by Roger Zelazny, has a cold blue right eye and a warm brown left eye, indicative of his being either (or both) a mutant and/or a kallikanzaros, a Greek trickster spirit changeling.
• Cloud Strife of Final Fantasy VII has blue eyes with green highlights. Known in the game as "Mako Eyes", the unnatural green discoloration occurs when a person is exposed to Mako energy.
• Yuna of Final Fantasy X and Final Fantasy X-2 is known for being heterochromatic (one blue eye, one green eye) due to her mixed Al Bhed heritage
• Mary "Lady" Arkham from Devil May Cry 3: Dante's Awakening has one blue/green eye and one red eye. Her father also has the same eye coloration, but the hues are paler.
• Montgomery from the 1997 Nowhere has one green eye and one blue one
• Jason, Stryker's son, from X2: X-Men United has one blue and one light brown. When he is being used to control Patrick Stewart's character, he appears as a little girl with the same eye colors.
• Ysanne Isard from Star Wars Extended Universe has one red and one blue eye
• Gaeriel Captison, also from the Star Wars Extended Universe, has one green eye and one gray
• Asuna Kagurazaka from the Japanese (神楽坂 明日菜 Kagurazaka Asuna) manga/anime "Negima" has one blue and one dark green eye.
• Oskar von Reuentahl from the anime/novel/manga series Legend of the Galactic Heroes has one blue and one brown eye.
• Kanzaki Urumi from the Japanese manga/anime "Great Teacher Onizuka" has a brown left eye and a blue right eye.
• Phoenix (the bad guy played by Wesley Snipes) in the movie Demolition Man
• Subaru Sumeragi of Japanese manga X/1999 presumably has heterochromia after the events of the 17th volume of the series (he has one grey-green eye; his right eye was previously blinded then replaced with the hazel colored eye of his dead lover, Seishirou Sakurazuka)
• Hatake Kakashi of manga Naruto possesses one dark eye while his red left eye is actually an implant of the sharingan.
• Count D of the manga/anime "Pet Shop of Horrors" has one purple eye and one golden eye.
• Mayumi Thyme of the Japanese game/manga/anime Shuffle! has one red and one blue eye which reflects her half human, half demon nature.
• Laura from the novel Maya by Jostein Gaarder is described as having one green eye and one brown eye
• Shani Andras, a biological CPU of Gundam Seed has different colored eyes
• Delirium from the comic "The Sandman", one of the earliest and best known examples. Delirium is a floaty, crazy character with one eye lime green and the other blue with silver speckles.
• Suiseiseki and Souseiseki from the anime and manga Rozen Maiden each have one green eye and one red eye.
• In the original The Crow comic book miniseries, the protagonist, Eric Draven, has one light and one dark-colored eye (as the comic is in black and white, exact colors are indeterminable) as a result of a ruptured iris following two gunshot wounds to the head.
• In H. P. Lovecraft's story "The Lurking Fear" members of the Martense family of upper New York all share a "hereditary dissimilarity of eyes, one generally being blue and the other brown."
• Spike Spiegel of the anime Cowboy Bebop has brown eyes, but one eye is colored lighter than the other. He says he lost his original eye in an accident, and since then he sees the past through one eye and the present through the other.
• Ephram Brown from Everwood on the WB
• Phèdre nó Delaunay, the main character of Jacqueline Carey's Kushiel's Legacy series of novels, has a scarlet mote in her left eye.
• Tyrion Lannister from A Song of Ice and Fire by George R.R. Martin, has mismatched eyes.
• G.U.N. Commander from Shadow the Hedgehog has one blue eye and one mauve.
• Wally, the werewolf from the webcomic Zebra Girl, has complete heterochromia, and his eye colors switch around when he changes between his human and wolf forms.
• The War God, Homura, from the anime/manga Saiyuki has one golden eye and one blue eye.
• Murdoc Niccals, bass player for Gorillaz, has one red eye on the left and one black eye on the right.
• Several of Capcom's characters from various games have Heterochromia. Darkstalker's Donovain Baine has one brown eye and one demonic eye due to being half-vampire. Both Akane Jubei Yagyu and her uncle Munenori Yagyu from Onimusha: Dawn of Dreams each have a right red eye, due to their Oni heritage. Unlike Akane, who was born with hers, Munenori received his eye from his grandmother, who gave it to him in order to save his own life.
• President Charles Logan of 24 has a green eye and a blue eye.
• In Wayne's World 2, Garth and his buddy try not to notice the eyes of Jerry Segel who says he is a partial ocular albino, revealing his differently colored eyes.
• Proximo, the retired gladiator character from the Ridley Scott film Gladiator, has one green and one blue eye.
• Professional wrestler Glen Jacobs' persona of Kane has one blue (left) eye and one sky blue (right) eye. He really wears a contact lens on his right eye.

External links

• "Heterochromia" by Dr. Peter G. Swann
• Windows of the Soul / Ron Padova

See also

• List of systemic diseases with ocular manifestations