Visual evoked potentials in diagnostics of optic neuropathy associated with renal failure

Chronic renal failure is associated with many neurological complications. Due to accumulation of uremic neurotoxins axonal degeneration with its secondary demyelination occurs, which results in development of polineuropathy in 60‑100% of patients with chronic renal failure. One of the most severe peripheral neuropathy is optic neuropathy. It is associated with visual deterioration and reduction in quality of life. Symptoms of the optic neuropathy may appear either before or after dialysis therapy. They often worsen after renal transplant, probably due to immunosuppressive regimen. Early diagnostics of the optic neuropathy became possible by using visual evoked potentials (VEP). This reliable, sensitive and noninvasive technique provides a direct measure of subclinical impairment of visual pathways. Among hemodialysed or immunosupressed patients one can observe abnormal VEP parameters - especially prolonged latency of the P100 component, less often fluctuation of its amplitude. These alterations are pronounced even if clinical examination reveals no abnormalities. This review presents a summary of current use of visual evoked potentials in monitoring of patients with chronic renal failure.