when a 12-year-old boy , suffering from blurred vision for about 1 month , visited the ophthalmological clinic of hirosaki university hospital , only a chiasmal lesion was suspected because neuro-ophthalmological examination revealed no more than ophthalmic signs , such as bilateral diminution of vision ( vd , vs = 0.2 ) , concentric narrowing of visual fields and slight bilateral papilledema .
C0015392
ophthalmic
C0042789
vision