Albinotic characteristics in congenital nystagmus.

We studied 26 white patients (19 males and seven females), ranging in age from 1 to 57 years, with congenital nystagmus for the characteristics of albinism. None of the patients was known to be an albino and none had readily apparent signs of albinism. The study also included 26 controls matched by age, sex, race, and complexion. Twelve of the 26 patients with congenital nystagmus had one or more of the following characteristics: detectable iris transillumination (six of 25 patients), choroidal depigmentation (four of 22 patients), and abnormal tanning history (eight of 26 patients). Iris transillumination and abnormal tanning were not found in any of the controls but two controls showed choroidal depigmentation and one showed blunting of the macular reflex (this was determined to be age-related). These differences were significant for iris transillumination (P = .01), blunting of the macular reflex (P = .01), and abnormal tanning (P = .002) but not significant for choroidal depigmentation (P = .38). Within the group of patients with congenital nystagmus, iris transillumination was significantly associated with blunting of the macular reflex (P = .03), choroidal depigmentation (P = .03), and abnormal tanning (P = .004) but not with eye color (P = .16) or visual acuity (P = .33). These findings suggested that many patients with apparently isolated congenital nystagmus may have subclinical albinism or a form of albinoidism.