Development and Significance of Heterochromia of the Iris

Sectoral iris heterochromia and retinal pigment variation in 13q-syndrome

“…8 Heterochromia of the iris is caused by alteration of iris color and structure with either hypopigmentation and hypoplasia, or hyperpigmentation and hyperplasia, which occurs as a variation within an iris or between the two irides. 9 Although most often benign, congenital heterochromia has been associated with iris malformations, neonatal infection, Waardenburg syndrome, Bremer syndrome, Romberg syndrome, congenital Horner syndrome, Parry-Romberg syndrome, congenital oculodermal melanocytosis, tuberous sclerosis, and sector iris pigment epithelial hamartoma. 9,10 Acquired heterochromia has been associated with trauma, neoplasms, chronic inflammation, carotid artery stenosis or occlusion, cranial arteritis, central retinal artery or vein occlusion, diabetes mellitus, Horner syndrome, hemosiderosis, iridocorneal endothelial syndrome, and heterochromic cyclitis of Fuchs.…”

Vitiligo and Other Hypomelanoses of Hair and Skin

“…That male eunuchs have pale skin and tan poorly suggests a yet undefined action of androgens on melanin pigmentation. In vivo studies have shown that testosterone increases cutaneous melanogenesis [174] but seems to have no consistent effect in humans [137] or animals [175].…”

Focal cortical dysplasia and heterochromia of the iris

“…Associated asymmetry of eye colour, however, has not been reported. Though HI may occur in healthy individuals as a rare variant,1 in this patient it was likely related to the brain malformation,2 in view of the affected iris of variegated colour being ipsilateral to the somatic findings, and the association with an ipsilateral eighth nerve deficit 3. Neurological conditions associated with HI include Sturge–Weber syndrome, congenital Horner's syndrome and Waardenburg's syndrome 4.…”