X linked ocular albinism in Japanese patients.

Thirteen affected Japanese male patients and 13 female carriers with X linked ocular albinism from seven families were examined to assess their clinical findings and to compare them with those of white and black patients. Affected Japanese patients had poor visual acuity, horizontal nystagmus, macular hypoplasia, and loss of stereopsis. Some affected patients had non-albinotic fundus with moderate pigmentation. The amount of pigment in the fundus varied among affected patients and appeared to be between that of the white and black patients. All affected patients had brown irides that show no translucency. Interestingly, two affected patients had megalocornea and a third affected patient had posterior embryotoxon. All female carriers exhibited good visual acuity, normal eye position, stereopsis, brown irides without translucency, and the typical mosaic pattern in the fundus. The pigmented iris and fundus made the correct diagnosis of these affected patients difficult. Nine affected patients (70%) had been diagnosed initially as having congenital nystagmus, with or without macular hypoplasia, until they were reviewed for this study.