异常垂直注视视差对间歇性外斜视患者立体视觉的影响

Effect of abnormal vertical fixation disparity on stereoacuity in intermittent exotropia

目的分析间歇性外斜视患者存在的异常垂直注视视差对其立体视觉的影响。设计病例对照研究。研究对象2016年7月至2017年2月北京同仁医院新诊断的104例间歇性外斜视患者和128名正常对照。方法使用知觉眼位检查对正常对照人群进行检测,确定垂直知觉眼位正常值范围(<x+1.64 s);根据是否超过垂直知觉眼位的正常值范围将间歇性外斜视患者分为不伴和伴有异常垂直知觉眼位两组,检测并比较两组患者近距离、中距离立体视觉的差异。主要指标垂直知觉眼位、近距离和中距离立体视觉。结果不伴有异常垂直知觉眼位患者的近距离立体视(2.21±0.34)和中距离立体视(2.09±0.23)均优于伴有异常垂直知觉眼位的患者(2.40±0.44;2.25±0.31)(t=-2.43,P=0.02;t=-2.97,P<0.01),而两组之间的年龄(P=0.19)、双眼间等效球镜差值(P=0.12)、看远看近水平斜视度(P=0.53、0.38)、分开运动破裂点(P=0.70)、辐辏运动破裂点(P=0.94)和融合范围(P=0.70)均无统计学差异。结论间歇性外斜视患者中存在的异常垂直注视视差可能加重患者的立体视觉损伤。

Objective To analyze the abnormal vertical fixation disparity which coexists with intermittent exotropia(IXT)and its influence on stereoacuity.Design Case control study.Participants 104 newly diagnosed IXT patients and 128 controls in Beijing Tongren Hospital from Jul 2016 to Feb 2017 were involved.Methods Perceptual eye position(PEP)test was performed on normal controls to get normal range(<x+1.64 s).The IXT patients were divided into two groups according to whether their vertical PEP exceeded normal range abnormal vertical PEP(group and normal vertical PEP group).Stereoacuity was measured for both near and medium distances.The differences of stereoacuity were compared between the two groups.Main Outcome Measures PEP test,stereoacuity measured for both near and medium distances.Results The near and medium distance stereopsis were better in normal vertical PEP group(2.21±0.34,2.09±0.23)than abnormal vertical PEP group(2.40±0.44;2.25±0.31)(t=-2.43,P=0.02;t=-2.97,P<0.01,respectively).However,no statistic differences were found between the two groups in age(P=0.19),interocular difference in spherical equivalent(P=0.12),near and far horizontal deviation(P=0.53,0.38),break point of fusional divergence(P=0.70)and fusional vergences(P=0.94),fusion range(P=0.70).Conclusion Abnormal vertical fixation disparity coexisting with IXT may aggravates the damage of stereoacuity.