Development of visual function in hemihydranencephaly.

This study reports on the findings of longitudinal follow-up of visual function in a 12-year-old girl affected by congenital right hemihydranencephaly. This extremely rare unilateral brain malformation allowed the authors to gather new information on neuronal plasticity and functional compensations of the visual system across a period of 10 years. An extension of the preserved right visual hemifields above the middle line and strategical eye or head positions developed to increase visual functions are discussed. In addition, ophthalmological and orthoptical findings, as well as the development of monocular grating and linear acuity, are described.