Familial aniridia with preserved ocular function.

Of 76 members of a large pedigree with familial aniridia, 61% of the 38 affected patients had visual acuity of 6/9 (20/30) or better and only 5% had acuity of 6/60 (20/200) or worse. Cataracts were present in 18% of affected patients; glaucoma in 13%; and strabismus in 34%. Sixteen percent of affected patients had strabismic amblyopia. No patient had nystagmus or corneal pannus. The good visual acuity in this family, as compared to that in others, indicates that the absence of iris tissue alone cannot account for the severe visual problems usually associated with aniridia.