A Preliminary Investigation Of Multifocal Visual Evoked Potentials In Anisometropic Amblyopia Children

Objective We study the characteristics of mfVEP and P-VEP inanisometropic amblyopia eye and the non-amblyopiafellow eye, in order to evaluate the mechanism ofanisometropic amblyopia and provide a new methods for their diagnosis.Methods mfVEP and P-VEP data from 56 anisometropic amblyopia children were analysed and compared with those 60 normal eyes obtained from 30 children.Results1. In the control group,neither the amplitude nor the latent period of mfVEP and P-VEP was different among the different sexes, ages and eyes(p>0.05). The amplitude of mfVEP rapidly reduced with the increase of the eccentricity, with the highest in the 10° central visual field and only 2% in the peripheral areas .2. Of the control group in mfVEP, the LN1-P1 was stableacross the full visual field, however the LPi-N2was longer in central visual field than in the peripheral areas, and LP1-N2 was significantly longer than LN1-P1.3. Using the amplitude and latent to assess the visual function, it's found that the non-amblyopia fellow eyes has the best function, then the control eye, and the amblyopia eye has the worst.4. In anisometropic amblyopia eyes, the amplitude of mfVEP were significantly attenuated in the 10° central visual field, and the phenomena gradually reduced with the increase of the eccentricity.5. No significant differences were found among different degrees of anisometropic amblyopia eyes in mfVEP or P-VER6. Correlation coefficient between degree of amblyopia eyes and anisometropic scole is 0.368(p<0.05).Conclusions1. In normal eyes, the amplitude of mfVEP were attenuated with the increase of the eccentricity, this character demonstrated good correspondence with the visual acuity changes and the topography of visual field. Amplitude differences between subjects remain a possible factor inthe anatomic variation of the visual cortex. mfVEP demonstrated good correspondence with P-VEP and additionally suggested "objective sight" in assessing visual function .2. Components N1-P1 and P1-N2 of mfVEP originated from different anatomic cells.3. The non-amblyopia fellow eyes has the best visual function, then the control eye, and the amblyopia eye has the worst .It may be showed that "monocular suppressed" resulted in anisometropic amblyopia eye and "monocular excited" in the fellow eye.4. In anisometropic amblyopia eyes, disfunction and morphology disorder maybe exist through the full visual pass from the ganglion cells to the visual cortex but not a solo lamina.5. Mechanism of anisometropic amblyopia differs from other kinds of amblyopia.6. The more different diopters between the two eyes, the more possibilities the children develop anisometropic amblyopia.