Contributor: Gordon K. Klintworth
Imperfect albinism (tyrosinase-negative oculocutaneous albinism, oculocutaneous albinism type IA) is a distinct inherited type of oculocutaneous albinism with an autosomal recessive mode of inheritance. Affected persons have diminished pigmentation of the skin, hair, and eyes. They also have an abnormal macula (macular hypoplasia [hypoplasia - macula] with abnormal vascular pattern), nystagmus, transparent irises, photophobia and a defective decussation of nerve fibers in the optic chiasm.Visual acuity is also decreased and factors that probably contribute to visual impairment include light scatter, light-induced damage to the retina, macular hypoplasia, and abnormal retinogeniculostriate projections. The defect in tyrosinase-negative oculocutaneous albinism is an inability to synthesize tyrosinase.