[Multifocal visually evoked responses in two children with optic neuritis].

PURPOSE: Central visual functions of two children with idiopathic optic neuritis were analyzed and followed in the course of the disease by using multifocal visually evoked potentials (mVEP) and other ophthalmological tests.

SUBJECTS AND

METHODS

Two girls 10 and 11 years of age with unilateral optic neuritis participated in this study. At the initial onset of the disease, visual acuity of the patients was below 20/400 and severe central visual field impairment was found in the affected eyes. There were no abnormal neurological or radiological findings suggesting multiple sclerosis in these patients. The mVEPs were recorded with a stimulus of 37 hexagons composed of black and white triangles subtending 35 degrees of visual angle.

RESULTS

The amplitude of mVEPs from many stimulating locations was severely reduced in the course of the recovery of these patients. Although visual acuity and perimetric sensitivity in the affected eyes recovered to normal after steroid pulse therapy, the amplitude of mVEPs still remained 1/3 to 1/2 of that of the opposite healthy eye. The mVEPs gradually recovered to near the level of the opposite healthy eyes at the latest examination.

CONCLUSIONS

Recovery from the central visual impairment due to infantile optic neuritis is more gradual than that suggested by subjective ophthalmological examinations. There is still optic nerve dysfunction after visual acuity and visual field have recovered to normal. The mVEP is one of the most sensitive tools for detecting optic nerve dysfunction in patients with optic neuritis.