Visual field loss associated with vigabatrin: pathological correlations

Pathological changes are reported in the anterior visual pathways of a 41 y ear old man with complex partial seizures treated with vigabatrin who devel oped bilateral visual field constriction. There was peripheral retinal atro phy with loss of ganglion cells and loss of nerve fibres in the optic nerve s, chiasm, and tracts. No evidence of intramyelinic oedema was seen. These findings suggest that the primary site of injury lies within the ganglion c ells in the retina. The degree of atrophy seen would suggest that the visua l field loss is irreversible.