The lateral geniculate nucleus in human anisometropic amblyopia.

Experimental amblyopia in animal models causes a reduction of cell sizes in lateral geniculate nucleus (LGN) laminae connected with the amblyopic eye. However, direct evidence that the human amblyopic visual system is affected in a similar manner has been lacking. Histologic study of the LGNs from a patient with ophthalmologically confirmed anisometropic amblyopia shows a decrease of cell sizes in the parvocellular layers innervated by the amblyopic eye. This decrease was more pronounced in laminae receiving crossed fibers. To our knowledge this is the first report about structural alterations in the afferent visual pathway of a human amblyope and the data reaffirm the validity of the monkey model for further study of the basic mechanisms in amblyopia.