【摘要】 目的:评价单眼弱视者的空间视觉缺损及其与弱视程度的相关性,并基于M-P视觉通道理论分析单眼弱视空间视觉缺损的机制。方法:采用ETDRS数字视力表和OptecR6500视功能检测仪检测111例7~34岁单眼弱视者弱视眼和非弱视眼的视锐度和对比敏感度函数,通过视锐度和对比敏感度函数衍生计算对比敏感度函数曲线下面积(AULCSF)、峰值对比敏感度(S max)、S max所对应的空间频率(Fr max)以及截止空间频率(CutSF),分析单眼弱视者的空间视觉缺损特点及其与弱视程度的相关性。结果:单眼弱视者的弱视程度与双眼对比敏感度AULCSF差值呈负相关(r=-0.83,P<0.01),弱视眼视锐度与AULCSF、CutSF、S max、Fr max呈负相关(r值分别为-0.68、-0.80、-0.73和-0.56,P<0.01)。不同程度弱视患者视锐度、AULCSF、S max、Fr max及CutSF间差异均有统计学意义(P<0.01)。不同程度弱视者非弱视眼视锐度、AULCSF、S max、Fr max及CutSF差异均无统计学意义(P>0.05)。轻度弱视者的弱视眼与非弱视眼AULCSF和Fr max差异也无统计学意义(P>0.05),S max和CutSF差异有统计学意义(P<0.05);而中重度弱视者弱视眼与非弱视眼AULCSF、S max、Fr max及CutSF差异均有统计学意义(P<0.01)。不同程度弱视者弱视眼在各空间频率下对比敏感度差异均有统计学意义(P<0.01),而非弱视眼间差异无统计学意义(P>0.05)。结论:视锐度与AULCSF、CutSF、S max、Fr max在弱视者空间视觉评价时呈现趋势一致性。随着弱视程度的加重,弱视眼的整体空间视觉功能逐渐下降,视觉系统的高频端分辨率逐渐减弱和最佳对比度识别能力降低,最适空间频率向低空间频率偏移。在轻度弱视者中,M细胞通道无明显异常,P细胞各亚型的敏感性下降;而中高度弱视者中,M和P细胞通道均受到不同程度的损伤,且以P细胞通道受损为主。更多还原

【Abstract】 Objective: To investigate the relationship between the characteristics of spatial vision deficit and the degree of amblyopia in monocular amblyopes,and to analyze its mechanism with the theory of Magnocellular and Parvocellular pathways. Methods: One hundred and eleven patients with monocular amblyopes aged 7-34 were included in this study. Distance best corrected visual acuity( BCVA) in logMAR units and contrast sensitivity function test were performed on both eyes in all patients with ETDRS digital visual chart and functional test system OPTECR6500. The spatial vision of amblyopic and non-amblyopic eyes was evaluated by the AULCSF,S max,Fr max and cutSF derived from the curve of contrast sensitivity function. Results: The degree of amblyopia was significantly correlated with the difference of AULCSF between the amblyopic and non-amblyopc eyes( r =-0. 83,P < 0. 01). BCVA of amblyopic eyes was significantly correlated with AULCSF,CutSF,S max,Fr max( r =-0. 68,-0. 80,-0. 73,-0. 56,respectively; P <0. 01). In amblyopic eyes,significant difference in BCVA,AULCSF,S max,Fr max and CutSF was seen among different amblyopic groups( P < 0. 01),which was defined by the degree of amblyopia. In non-amblyopic eyes,no significant difference in BCVA,AULCSF,S max,Fr max and CutSF was noted among different amblyopic groups( P > 0. 05). In mild amblyopes,no significant difference in AULCSF and Fr max was found between the amblyopic eyes and non-amblyopic eyes( P > 0. 05),while S max and CutSF were significantly different. However,in moderate and severe amblyopes,significant differences in BCVA,AULCSF,S max,Fr max and CutSF was seen between the amblyopic and non-amblyopic eyes( P < 0. 01). In amblyopic eyes,significant difference in contrast sensitivity was noted in all kinds of spatial frequencies among different amblyopic groups( P < 0. 01),and in non-amblyopic eyes,significant differences in contrast sensitivity was not seen in all kinds of spatial frequencies among different amblyopic groups. Conclusions: The AULCSF,CutSF,S max and Fr max are accorded with visual acuity for evaluation of the spatial vision of amblyopia. As the severity of amblyopia increases,the overall function of spatial vision in amblyopic eyes gradually decreases,the resolution ability of high spatial frequency is gradually weaken,the peak of contrast detection function gradually descends,and the optimal spatial frequency for contrast detection offsets toward low level of spatial frequency. Mild monocular amblyopia produces spatial contrast sensitivity loss in high spatial vision,suggesting there may be decreased sensitivity of the Parvocellular pathway,and no significant anomalous processing of Magnocellular Pathway. Whereas,in moderate and severe amblyopes,a generalized loss of sensitivity is observed at each spatial frequency. This result shows that both Magnocellular and Parvocellular pathways are damaged in different degrees,especially in Parvocellular pathway.更多还原