Ocular Albinism with Changes Typical of Carriers* By

OCULAR albinism is a form of incomplete albinism in which the lack of pigment is chiefly confined to the eyes. The condition is relatively rare, but since it was described for the first time by Nettleship (1909), it has occasionally been demonstrated in various families. Nettleship was aware that the disease-producing gene was sex-linked, but assumed it to be recessive; recent investigations have since proved that the sex-linked gene of the condition is intermediate in its expression. The ocular symptoms encountered in males with ocular albinism are also well known in generalized albinism. Affected individuals suffer from impaired vision and undulatory nystagmus; the retinae are poor in pigment; the choroidal vessels are seen with great clearness, and the macular areas are hypoplastic, lacking the yellow colour normally seen in red-free light (Vogt, 1924). The irides are bright and translucent, so that the pupils may appear faintly red. Strabismus and astigmatism are usually present. In addition, head nodding is often seen in early childhood. Attention has been focused particularly on this complex of characteristic symptoms in males, whereas little interest has been taken in the apparently unaffected females. However, Waardenburg (1947) was able to show, by the translucence of their irides, that these heterozygous females were carriers. A few years later, Falls (195 1) established what had been rendered likely by Waardenburg's observation, viz. that ocular albinism has an intermediate sex-linked mode of inheritance; he described a peculiar ophthalmoscopic picture which he had observed in all female carriers in two American families in which male members exhibited ocular albinism. Vogt (1941) had previously described these ophthalmoscopic changes in a female carrier, but it seems that he did not then realize the significance of his observation. Francois and Deweer (1953) later described a large Belgian family of 179 members who exhibited exactly the same changes as those observed by Falls.