Electrophysiologic evidence for normal optic nerve fiber projections in normally pigmented squinters.
The Siamese cat, a type of albino, has a visual pathway anomaly in which too many optic nerve fibers cross at the optic chiasm, and also frequently has strabismus. The correlation of strabismus with this defect suggests that a similar pathway defect without pigmentation anomalies, may be the cause of much human strabismus. Creel, Witkop, and King have used evoked potential methods to show that such a pathway defect likely occurs in the human albino. While unpublished control experiments verified their results on human albinos, no such defect has been found in the normally-pigmented human squinter. It is concluded that the visual pathway anomaly is limited to albinism and is not a likely cause of most human strabismus.
D000293:Adolescent; D000328:Adult; D000417:Albinism / Q000503:physiopathology; D000818:Animals; D002415:Cats; D002675:Child, Preschool; D005071:Evoked Potentials; D005127:Eye Color; D005830:Geniculate Ganglion / Q000503:physiopathology; D006801:Humans; D008959:Models, Neurological; D009900:Optic Nerve / Q000503:physiopathology*; D013285:Strabismus / Q000503:physiopathology*; D014793:Visual Cortex / Q000503:physiopathology; D014795:Visual Pathways / Q000503:physiopathology*