Albinism | Oculocutaneous albinism | Ocular albinism
    1What is albinism?

    Albinism is the absence of melanin pigment that can occur systemically (oculocutaneous) or primarily involving the eyes (ocular).

    2What are the typical findings of this condition?

    Oculocutaneous albinism can be divided into two types, tyrosinase-positive and tyrosinase-negative, using hair root studies. Tyrosinase is an enzyme responsible for converting tyrosine to melanin. The eye findings associated with oculocutaneous albinism include poor visual acuity, usually 20/80 to 20/400, nystagmus, hypopigmentation of the iris with transillumination defects, macular hypoplasia, and hypopigmented fundus. The poor visual acuity is due to macular hypoplasia and “miswiring” of the optic neurons in the chiasm. Tyrosinase-positive oculocutaneous albinism shows progressive increased pigmentation, as they are bale to produce melanin. Tyrosinase- negative oculocutaneous albinism is a severe hypopigmentation disorder that tends to be static and is associated with poorer visual acuity and legal blindness. Both positive and negative oculocutaneous albinism are inherited as autosomal recessive traits.


    Ocular albinism is hypopigmentation that is localized to the eye. Patients with this condition may have brown or dark hair and will not look like the typical patient with albinism. In contrast to the oculocutaneous type, ocular albinism is usually inherited as an x-linked trait.

    3What diagnostics are done for patients considered to have albinism?

    VEP findings suggest an excessive decussating of neurons at the chiasm. Hair root studies are done to determine tyrosinase activity.

    4Can anything be done to improve the visual acuity?

    Correcting the associated refractive error, particularly astigmatism may improve acuity, or sometimes the severity of nystagmus. Tinted glasses will help in decreasing the sensitivity to light.

    Dr. Barbara Roque
    Dr. Barbara Roque
    Dr. Barbara Roque is a an ophthalmologist whose practice includes general ophthalmology (which includes cataract surgery) with subspecialty work in pediatric ophthalmology, strabismus and ophthalmic genetics.
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