Electrophysiological assessment of optic neuropathies in neuro‐ophthalmological practice

Purpose Clinical challenge in diagnosis of optic neuropathies are atypical cases of either unknown visual loss or clinical cases in which the cause is identified, however, assessment of the visual function by psychophysical and morphological methods is not sufficiently accurate to assess the damage caused by lesion, or when functional follow‐up is needed to assess the course. Such cases include inflammatory, compressive, paraneoplastic, infiltrative, toxic/nutritive or atypical demyelinating optic neuropathies. Methods Electrophysiological methods will be interpreted with clinical history and presentation of clinical cases. Psychophysical methods and morphological presentation will be discussed in the context of why electrophysiology was needed either to clarify the diagnosis or to assess the functional status of the visual system. Results Electrophysiological methods were informative in either dissociating the retinal involvement from that of optic nerve and to asses the functional preservation of the visual pathway. It is of importance that mfERG and pattern ERG can add to the diagnosis on macular disfunction where visual evoked potentials alone would be diagnostic for optic neuropathy. Conclusion In neuroophthalmology, electrophysiological testing has its value especially in atypical cases and in situations where additional characterisation or functional assessment is needed. It is of importance to be able to dissociate functional characteristics of different components of visual pathway to assess the correct diagnosis and to asses whether the optic nerve may be endangered by progressive process, not readily discernible by other methods.