Objective To investigate the association between pupil location and lateral coma before and after wearing a rigid gas-permeable contact lens (RGPCL).Methods In this prospective case control study,corneal topography was taken from 42 bare eyes of 21 subjects before lens wear and 1 month after wearing the RGPCL and corresponding wavefront aberrations of the anterior corneal surface were calculated with a Matlab program.Pupil location and diameter were measured by corneal topography.Wavefront aberrations of the whole eye were taken with a WAVE analyzer for the same 42 eyes with and without RGPCL.And all the wavefront aberrations were calculated within a 6.0 mm area.Results The lateral shift of the pupil center was observed to be significantly temporal both for right eyes (-0.067±0.141 mm for bare eyes,and-0.103±0.129 mm after lens wear,t=2.240,P＜0.05) and left eyes (0.059±0.159 mm for bare eyes,and 0.114±0.132 mm after lens wear,t=-3.371,P＜0.01) after wearing RGPCL.And pupil diameter increased accordingly (3.69±0.61 mm for bare eyes,and 3.91±0.49 mm after lens wear,t=-2.865,P＜0.01).For bare eyes,lateral coma was significantly different from baseline when wearing RGPCL.The mean values for the baseline and lens wear were-0.104±0.075 μm,0.019±0.050 μm (right eyes,t=5.697,P＜0.01) and 0.127±0.074 μm,-0.001±0.079 μm (left eyes,t=5.113,P＜0.01) for the cornea and 0.012±0.072 μm,0.097±0.054 μm (right eyes,t=5.291,P＜0.01) and-0.038±0.071 μm,-0.099±0.051 μm (left eyes,t=4.387,P＜0.01) for the whole eye.The lateral shift of the pupil center was significantly correlated with the lateral coma of the cornea (r=-0.583,P＜0.01),whole eyes (r=-0.534,P＜0.01) and pupil diameter (r=0.501,P＜0.01).Conclusion The results suggest that the temporal shift of the pupil center could change the pattern between the cornea and whole eye from compensation to passive.And the pupil diameter may be one of the reasons for this variation.%目的 分析RGPCL配戴前后,全眼球和角膜像差的变化情况以及与瞳孔中心位移之间的关系.方法 前瞻性病例自身对照研究.21例志愿者(42眼),平均年龄(26.7±4.1)岁,平均屈光度(-3.59± 1.36)D,散光度(-0.67±0.24)D;用鹰视角膜地形图测量瞳孔中心相对于角膜中心的偏移量、瞳孔直径以及角膜像差,鹰视波前像差仪测量裸眼的全眼球像差.然后由同一名视光师给予验配美尼康RGPCL,在配戴RGPCL 1个月后回访,用相同仪器分别测量戴镜时的瞳孔中心偏移、瞳孔直径、角膜像差和全眼球像差.统计分析6 mm直径下的前4阶14项波前像差.采用配对t检验和相关分析对数据进行分析.结果 配戴RGPCL 1个月后,双眼瞳孔中心向颞侧水平偏移,瞳孔直径轻微增大,其变化量如下:①水平位移:右眼戴前为(-0.067±0.141)mm,戴后(-0.103±0.129)mm(t=2.240,P＜0.05);左眼戴前为(0.059±0.159)mm,戴后(0.114±0.132)mm(t=-3.371,P＜0.01).②瞳孔直径:戴前为(3.69±0.61)mm,戴后为(3.91±0.49)mm(t=-2.865,P＜0.01).角膜和全眼球的水平彗差变化均有统计学意义:①角膜水平彗差减少,右眼戴前为(-0.104±0.075)μm,戴后(0.019±0.050)μm(t=-5.697,P＜0.01),左眼戴前为(0.127±0.074)μm,戴后(-0.001±0.079)μm (t=5.113,P＜0.01);②全眼球水平彗差增加,右眼戴前为(0.012±0.072)μm,戴后(0.097±0.054) μm(t=-5.291,P＜0.01);左眼戴前为(-0.038±0.071)μm,戴后(-0.099±0.051)μm (t=4.378,P＜0.01).在这些有变化的参数中瞳孔中心水平位移分别与角膜和全眼球水平彗差差值呈负相关(r=-0.583、-0.534,P＜0.01);并且瞳孔中心水平位移与瞳孔直径的改变有较大相关性(r=0.501,P＜0.01).结论 配戴RGPCL后,瞳孔中心发生颞侧向的水平位移,从而角膜和全眼球水平彗差也相应改变,原来的角膜和眼内彗差的互补平衡被打破.瞳孔直径的轻微增加可能是造成此种改变的原因之一.
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