| Objective The purpose of this study was to explore the characteristic changes of multifocal VEP and multifocal ERG in anisometropic amblyopia before and after Treatment, to investigate the change of stereoscopic vision amblyopic Children before and after treatment, and based on above information to evaluate the possible mechanism of amblyopia.Methods RETIScan 21 multifocal physiological instrument(German company Roland) was employed to record the change of amblyopia patients before and after treatment of m VEP and m ERG. The characteristic peak latency and amplitude response density were used as the analysis index of patients of anisometropic amblyopia, we analyzed from different retina areas including four quadrants, the second half side, nasal and temporal side, and six eccentricities. The graphic features were compared among the amblyopic eyes. the contralateral eye and control group; Once amblyopia patients reached normal patients, this is, visual acuity is up to 0.9 and maintained for 2 months, the multifocal physiological examination, Titmus stereogram and synoptophore, binocular vision were used to detect. Compared with before treatment; we analyzed graphic characteristics of anisometropic amblyopia by m VEP and m ERG, the correlation between the improvement of visual acuity and the changes of m VEP and m ERG, and before and after the treatment of anisometropic amblyopia and binocular visual function.Results 一. Graphic features of m VEP and m ERG in Normal control Group m VEP: We observed that the waveforms was opposite polarity on lower hemi field; semi field m VEP latency was longer than lower hemifield with significant difference(P < 0.05), semi field m VEP amplitudes density is lower than the lower hemifield( P < 0.05). On the other side, temporal visual field of m VEP characteristicpeak response of short latency in nasal visual field(P < 0.05) and temporal visual field of m VEP characteristic peak response amplitude density higher than nasal visual field(P < 0.05). At the six degree of centrifugation, the mean values of the latency of the m VEP characteristic peaks of the upper half of the field view were not significantly different(P > 0.05). But there was a significant difference in the amplitude response density of each half ring(P < 0. 05), Similar results were obtained from the lower half field of view. m ERG: we concluded that there was longer latency in the half of the field, the amplitude response densities was less than half of the visual field. But both of the latency and amplitude of the response density had no significant difference(P > 0.05); Characteristic peak latencies of m ERG in temporal visual field and nasal visual field were extended, response amplitude density was decreased, but there was no significant difference(P > 0.05); In six centrifugal, amplitude response densities of m ERG have significant difference P < 0.05) among deference Rings. There were significant difference(P > 0.05) in Six degrees of incubation period. Binocular vision of multifocal electrophysiology examination: m VEP in lower hemi field eyes by inspection response amplitude was bigger than monocular respectively inspected the maximal response amplitude(P < 0.05); the presence of m VEP binocular summation and m VEP in six centrifugal degrees, the sum of memory in the central 2.5 central region is obvious. We could not find obvious phenomenon of the sum in other loop ring region. We also didn’t observed obvious sum phenomenon in normal group m ERG. 二. Graphic features of multifocal VEP and multifocal ERG in anisometropic amblyopes before treatment m VEP:In the upper and lower half of the visual field, The amplitude density of m VEP reaction in the eyes of amblyopia was decreased compared with that of normal eyes, there was significant difference(P < 0.05); The response amplitude density was also decreased in the contralateral eyes of the amblyopia, but no significant difference(P > 0.05); Peak vision hemiamblyopia eye on the latency of contralateral eyes and normal eyes increased, there was significant difference(P < 0.05). compared with the contralateral eyes and normal eyes, there was no significant difference(P > 0.05);vision in the nasal temporal, amblyopic eyes than the contralateral eye response amplitude density decreased significantly and the latency was prolonged, there was significant difference(P < 0.05); In six degrees of eccentricity, The response amplitude density of the m VEP characteristic peak of the amblyopia eye was lower than that of the normal eye and the corresponding value of the contralateral eye, and there was significant difference(P < 0.05); However, compare with the contralateral eyes and normal eyes m VEP peak response Amplitude density, there was no significant difference(P > 0.05); Comparison of characteristic peak latency of m VEP in six eyes with amblyopia, Lateral eye and normal eye prolonged(P < 0.05). m ERG:In the upper and lower half of the visual field, The amplitude density of m ERG reaction in the eyes of amblyopia was decreased compared with that of normal eyes, there was significant difference(P < 0.05); The response amplitude density was also decreased in the contralateral eyes of the amblyopia, but no significant difference(P > 0.05); Peak vision hemiamblyopia eye on the latency of contralateral eyes and normal eyes increased, there was significant difference(P < 0.05). compared with the contralateral eyes and normal eyes, there was no significant difference(P > 0.05); vision in the nasal temporal, amblyopic eyes than the contralateral eye response amplitude density decreased significantly and the latency was prolonged, there was significant difference(P < 0.05); In six degrees of eccentricity, The response amplitude density of the m ERG characteristic peak of the amblyopia eye was lower than that of the normal eye and the corresponding value of the contralateral eye, and there was significant difference(P < 0.05); However, compare with the contralateral eyes and normal eyes m ERG peak response Amplitude density, there was no significant difference(P > 0.05); The latent period of the m ERG characteristic peak in the amblyopia eye was compared with that of the normal eye and the contralateral eye. No significant prolongation was seen in each ring.(P > 0.05). Graphics abnormal degree of Amblyopia eyes with m VEP and m ERG: The symmetry analysis of non eye m VEP and m ERG waveform of binocular anisometropic amblyopia,we found that the amblyopic eyes in the central area, caused maximum damage. With the increase of the degree of centrifugation, RAC decreases. The asymmetry coefficient of m VEP in the eyes of amblyopia has apositive correlation with the severity of amblyopia. Abnormal degree was bigger. Anyway, There was no significant correlation between the asymmetry coefficient of m ERG waveform and the degree of amblyopia. 三. Characteristic of waveform of multifocal VEP and multifocal ERG in Anisometropic amblyopia group after treatment m VEP:The characteristic peak latency and response amplitude density are basically the same without significant difference compared to the comparison of nasal and temporal perspective and comparison of upper and lower half visual field in amblyopia eyes; Compare with the lateral eye, the amplitude response density had no significant difference(P > 0.05); But the latency have prolonged with significant differences(P < 0.05); m VEP amplitudes density have increased significantly before treatment. Meanwhile, there are significant differences(P < 0.05). Compare to normal group, the amplitude of the response density in first and second Ring were decreased and the latency have prolonged. There are significant differences(P < 0.05). m ERG:The characteristic peak latency and response amplitude density are basically the same without significant difference(P > 0.05) compared to the comparison of nasal and temporal perspective and comparison of upper and lower half visual field in amblyopia eyes; Compare with the lateral eye, the amplitude response density had no significant difference(P > 0.05); But the latency have prolonged with significant differences(P < 0.05); m VEP amplitudes density have increased significantly before treatment. Meanwhile, there are significant differences(P < 0.05). Compare to Normal eye and Contralateral eye, the amplitude of the response density in the six centrifuge have significant differences(P < 0.05). 四. The binocular visual function before and after the treatment of anisometropic amblyopia 1.Titmus stereopsis examination and electrophysiology check: we have grouped into amblyopia with light, moderate and severe. Among three groups, the center stereopsis has gained significant difference(P < 0.05). In light group with amblyopia center stereops was better. Obviously, the greater the degree of amblyopia, The worse the stereopsis; after the comprehensive treatment of amblyopia, three group ofamblyopia has been significantly improved in stereo center. After treatment, light and moderate amblyopia has significant difference(P < 0.05), while, there was no significant difference(P > 0.05) compared with those before treatment; 2. Binocular vision of multifocal electrophysiology check: before treatment m VEP of light amblyopic was existed in half side view and nasal temporal vision. The amplitude of monocular in binocular response is greater than the maximum response amplitude(P < 0.05), severe amblyopic group has no significant sum phenomenon(P > 0.05); after the treatment, the m VEP of light and moderate amblyopic was lower in hemi vision and nasal temporal vision. The maximum response amplitude in binocular is larger than that of the monocular(P < 0.05); Severe amblyopia was lack of summation phenomenon; There are no eye sum phenomenon in the six centrifuge before treatment and after m VEP treatment.Conclusion 1. Patients with Amblyopia in the visual pathway, the visual cortex, as well as the retina are abnormal damage; the center area of m ERG and m VEP of amblyopia is significantly greater than the surrounding areas, which further support the central impairment theory of amblyopia. 2. The more severe amblyopia, the greater the degree of waveform of abnormal m VEP. But there were no any correlations with m ERG. 3. When the amblyopia were cured basically, the function of the retina was gradually repaired, but visual pathway, the visual cortex and the binocular visual function did not repair synchronously. 4. As a objective method,m VEP could be used in instructing binocular vision of Amblyopic children to some extent. |
PDF Full Text Request