A Study Of Multifocal Visual Evoked Potentials In Strabismic Amblyopic Children

Objective To compare the characteristic changes of multifocalVEP in strabismic amblyopia. To study the possiblemechanism of amblyopia and provide new data fortheir diagnosis.Methods A RETI scan^3.15multifocal electrophysiologicalsystem made in Germ an Roland Company was used togenerate a CRT combs stimulus matrix by means ofPattern-LT on a computer monitor. FOK(first ofkernel) responses was extracted and analyzed bythe RETI scan^3.15system. The mfVEP of both eyes of43 exotropic amblyopes and 37 esotropic amblyopesand 60 normal eyes were tested.Results1. In the central region of the N₁-P₁ amplitude densities(amp·P₁) and the P₁-N₁ amplitudes of mfVEP in the strabismus amblyopic eyes were significantly attenuated incompared with those normal eyes, these phenomenagradually reduced with the increase of the eccentricityincreased. Using the N₁-P₁ amplitude densities (amp·P₁)to assess the visual function, it's found that the esotropicamblyopic eye has the worst. No significant abnormality inlatency of strabismus amblyopic eyes was found across thefield. No significant difference of mfVEP was foundbetween mild amblyopia and serious amblyopia.2. The amp·P₁ of mfVEP at the tmoral visual field weresmaller than at the nasal visual field, no significantabnormality was found in those normal eyes, and thelatencies were delayed at the temoral visual field in allgroups.3. The abnormality of mfVEP in the esotropic amblyopiceyes was larger than that of the exotropic amblyopic eyes.CoclusionsThe results that mfVEP of amblyopia showedcharacteristic changes suggests that thepathological mechanism might existed in both theretina and the visual cortex.