Purpose of review: To summarize current technique, indications, and pitfalls of electrophysiologic testing used in ophthalmology.
Recent findings: Visual evoked potentials (VEPs) may be useful as an objective measurement of refractive error in complicated patients. VEP P100 latency was found superior to color vision and visual field in early stages of hydroxychloroquine maculopathy. VEP results can be predictive of visual recovery in traumatic optic neuropathy. Multifocal electroretinogram (ERG) or VEP can provide an objective assessment of visual field defects not yet present on automated perimetry in patients with glaucomatous and nonglaucomatous optic neuropathies. In patients with intraocular lymphoma, reduced amplitudes of all ERG components can be recorded, with the b-wave amplitude being most significantly affected.
Summary: Various visual electrophysiologic tests are useful to the ophthalmologist, each with different indications. The flash ERG is most useful in diffuse retinal disorders, whereas the multifocal ERG is superior in localized retinal disease. VEPs can be valuable in diagnosing optic neuropathies, nonorganic visual loss, and assessing visual function in infants or children.