视力正常成年人不同对比度下的视力的变化观察

摘要

目的 研究视力正常成年人不同对比度下的视力(CVA)及不同视标与背景的对比度、性别及年龄对CVA的影响.方法 横断面研究.入选标准:年龄20～70岁、裸眼视力≥0.8、等效球镜度为- 1.00～ +1.00 DS,散光度为-0.75～+0.75 DC,共入选353人.对受检者先行眼部及屈光检查,随后在暗室内使用多功能视力测试仪检测对比度为100％、25％、10％、5％的CVA.采用F检验、Spearman等级相关分析及配对t检验分别对检测数据进行分析.结果 在视力正常成年人中,随着多功能视力测试仪检查时视标与背景对比度的下降,各年龄组受检者的右眼、左眼和双眼的CVA均呈下降趋势(F右眼=1317.21,F左眼=991.09,F双眼=1223.87,P值均＜0.01).在同一对比度水平下,随着年龄增长,CVA显著下降(右眼CVA:F100％=10.86,P=0.000；F25％=11.54,P=0.000；F10％＝7.63,P =0.000;F5％ =4.88,P =0.001；左眼CVA:F100％=15.26,P =0.000;F25％=16.93,P=0.000;F10％=8.33,P =0.000;F5％=4.08,P =0.003;双眼CVA:F100％=11.87,P=0.000;F25％=15.08,P=0.000;F10％ =11.71,P=0.000;F5％ =9.51,P=0.000)；男性和女性100％及25％ CVA间的差异无统计学意义,但在10％及5％对比度下,女性的CVA平均值高于男性(右眼CVA:F100％=0.341,P=0.560;F25％ =0.434,P=0.510;F10％ =5.615,P=0.018;F5％ =9.492,P=0.002;左眼CVA:F100％ =0.212,P =0.645;F25％=0.132,P=0.716;F10％ =4.588,P=0.033;F5％ =4.812,P=0.029;双眼CVA:F100％ =0.775,P=0.379;R25％=1.043,p=0.308;F10％ =8.555,P =0.004;F5％ =5.630,P=0.018).ETDRS视力表检查结果与100％ CVA具有相关性(r右眼=0.632,r左眼=0.536,r双眼=0.456,P值均＜0.01),但100％ CVA的平均值均高于ETDRS视力表检查的视力平均值(t右眼 =20.70,t左眼=17.25,t双眼=23.47,P值均＜0.01).结论 年龄和不同对比度是影响CVA的重要因素.在低对比度下女性的CVA好于男性.%Objectives To evaluate the contrast visual acuity(CVA) in Chinese normal adults and to study the effects of different contrast levels between the optotypes and background,age and sex on the CVA.Methods It was a cross-sectional study.Three hundreds and fifty-three normal adults with age from 20 to 70 years were selected as the normal adults( naked visual acuity equal or more than 0.8,and equivalent sphere diopter - 1.00 - + 1.00 DS,astigmatic diopter - 0.75 - + 0.75 DC ).After conducting eye and refractive examination,all examinee were received the CVA measurements in the different coutrast levels between the optotypes and background ( 100％,25％,10％ and 5％ ) in the dark room by the multifunction visual acuity chart. SPSS 18.0 software package was used for one-way ANOVA( analysis of variance),Spearman correlation and paired t test.Results In the normal adults,CVA significantly decreased by the decrease of the contrast level between optotypes and background( FOD =1317.21,P ＜0.01 ;FOS =991.09,P ＜0.01 ; FOU =1223.87,P ＜ 0.01 ).In the same contrast level between optotypes and background,CVA significantly decreased by aging( F100％CVAoD =10.86,P =0.000;F25％CVAOD =11.54,P =0.000;F10％CVAOD =7.63,P =0.000;F5％CVAOD =4.88,P =0.001 ;F100％CVAOS =15.26,P =0.000;F25％CVAOs =16.93,P =0.000;F10％CVAOS =8.33,P =0.000;F5％CVAOS =4.08,P =0.003;F100％CVAOU =11.87,P=0.000;F25％CVAOU =15.08,P=0.000;F10％CVAOU =11.71,P =0.000;F5％CVAOU =9.51,P =0.000).CVA in the high contrast was similar between male and female,however,there was a significantly difference in CVA in the low contrast between male and female( F100％CVAOD =0.341,P =0.560;F25％CVAOD =0.434,P =0.510;F10％CVAOD =5.615,P =0.018 ; F5％CVAOD =9.492,P =0.002 ; F100％CVAOS =0.212,P =0.645 ; F25％CVAOS =0.132,P =0.716;F10％CVAOS =4.588,P =0.033 ; F5％CVAOS =4.812,P =0.029 ; F100％CVAOU =0.775,P =0.379 ; F25％CVAOU =1.043,P =0.308;F10％CVAOU =8.555,P =0.004;F5％CVAOU =5.630,P =0.018).A significantly correlation could be seen between the visual acuity of ETDRS and 100％ CVA( rOD =0.632,rOS =0.536,roU =0.456,all P ＜0.01 ).The 100％ CVA was higher than the visual acuity of ETDRS( tOD =20.70,tOS =17.25,tOU =23.47,all P ＜0.01 ).Conclusions Age and the different contrast levels between optotypes and background significantly affect CVA.In the low contrast between optotypes and background,CVA in the female is better than in male.