Investigation Of Multifocal Electroretinogram And Pattern Visual Evoked Potentials In Amblyopes

Objective To investigate the characteristic of the multifocal electroretinogram and pattern visual evoked potentials in amblyopic eyes.Methods The mERG and P-VEP of 28 anisometropic amblyopic eyes, 25 strabismic amblyopic eyes, 28 isometropic amblyopic eyes and 54 normal control eyes were tested.Results The NI wave and P, wave amplitude densities of mERG first order kernel and the PI wave amplitude densities of second order kernel in amblyopic eyes were significantly attenuated in the central region of the visual field, and these phenomena gradually reduced with the increase of the eccentricity. The NI wave and PI wave latencies of mERG first order kernel at the superior-temporal and inferior- temporal quadrant visual field were delayed than at the superior-nasal and inferior- nasal quadrant visual field in control eyes. The NI wave and PI wave amplitude densities of mERG first order kernel at the inferior- nasal quadrant visual field were larger than at thesuperior-temporal quadrant visual field. The N, wave and PI wave amplitude densities of mERG first order kernel at the temporal visual field were smaller than at the nasal visual field, and the latencies were delayed at the temporal visual field in all groups. The Pt wave amplitude densities of mERG second order kernel at the upper visual field were smaller than at the lower visual field in all groups, and other indexes were not statistically significantly different between the upper visual field and the lower visual field. Latencies of mERG among all groups were not significantly different. No significant difference of mERG was found among the three types of the amblyopic eyes. No significant difference of mERG was found between mild amblyopia and serious amblyopia. There were no linear correlations between visual acuity in amblyopic eyes and the indexes of mERG. There were significant differences between the sound eyes and the amblyopic eyes in mERG, but there were no significant differences between the sound eyes and the control eyes. The P|0o amplitudes of P-VEP in amblyopic eyes were significantly attenuated. The P)0o latencies of the P-VEP in amblyopic eyes were significantly delayed. No significant difference of P-VEP was found among the three types of the amblyopic eyes.Conclusions The results suggested that the pathological mechanism ofamblyopia might exit in both the retina and the visual cortex. The X ganglion cells in the retina of amblyopic eye were abnormal. The visual information transmitting time was normal in the retina of amblyopic eye. There were abnormal development and function in visual cortex. The mERG and P-VEP were objective methods for assessing visual function in amblyopia.