The clinical value of ophthalmic electrodiagnosis in children.

A group of 113 children with poor vision who had been referred to the Electrodiagnostic Clinic over a five year period were investigated for disease of the retina and optic pathway by electroretinography (ERG), electro-oculography (EOG) and visual evoked response (VER). The electrodiagnostic measurements were made using an automated system developed at Christchurch Hospital. The results of these investigations confirmed the clinical value of ophthalmic electrodiagnosis both as an aid in the diagnosis of these young patients and in determining their prognosis. In some cases it permitted an early detection of their condition. In addition the analyses of the ERG into rod and cone mediated responses helped to establish the diagnosis of hereditary retinal disorders and was particularly useful in the case of infants with nystagmoid movements of the eyes who were suspected of having poor vision. Interestingly 21 of the 113 patients were found to have functional visual loss. These patients complained of visual loss but subsequent examinations revealed their ocular findings, EOG, ERG and VER were all normal. The age of this functional visual loss group ranged from 7 to 15 years, with the average being 11.3 years (SD = 2.6 years). Furthermore they were a large group representing 32% of all the children between 7 and 15 years and in most cases were not happy at school.