近视眼患者对比度视力的相关因素分析

The contrast visual acuity and its associations in myopic eyes

目的探讨在明、暗环境下近视眼患者不同对比度视力的影响因素。设计前瞻性非对照性病例系列。研究对象123例近视眼患者右眼进行研究,等效球镜度在-0.50～-10.00 D,柱镜范围为0.00～-2.50 D,年龄17～47岁。方法在明、暗环境下测量100%、25%、10%、5%对比度视力,同时测量相应瞳孔大小。采用多元线性回归分析明暗环境下四种对比度视力与年龄、等效球镜度、瞳孔大小之间的关系。主要指标对比度视力、年龄、等效球镜度、瞳孔大小。结果在明环境下,100%对比度视力均与等效球镜度相关(t=2.551,P=0.012,R2=0.043),与年龄、瞳孔大小均无显著相关(P均>0.05);25%、10%、5%对比度视力均与瞳孔大小相关(t1=-4.111,P1<0.001,R21=0.123;t2=-4.434,P2<0.001,R22=0.14;t3=-5.766,P3<0.001,R23=0.216),与年龄无关(P均>0.05),与等效球镜度无关(P均>0.05)。在暗环境下,100%、25%对比度视力均与等效球镜度相关(t1=2.695,P1=0.008,R21=0.057;t2=2.429,P2=0.017,R22=0.047),与年龄无关(P均>0.05),与瞳孔大小无关(P均>0.05);10%、5%对比度视力均与瞳孔大小相关(t1=-2.305,P1=0.023,R21=0.042;t2=-2.424,P2=0.017,R22=0.046),与年龄无关(P均>0.05),与等效球镜度无相关(P均>0.05)。结论在明、暗环境下,100%对比度视力与等效球镜度呈负相关,与瞳孔大小无关;而10%、5%对比度视力受瞳孔影响较大。在明环境下,随着对比度的降低,视力受瞳孔大小的影响变大。相对于明环境,在暗环境下10%、5%对比度视力与瞳孔大小间相关性较弱。

Objective To investigate the associations of the contrast visual acuity in myopic eyes. Design Prospective non-controlled case series. Participants 123 right eyes of 123 subjects aged from 17 to 47 years-old with a spherical equivalent refraction （SE）varied from -0.5 D to -10.00 D were enrolled in this study. Methods MFVA-100 was used to measure contrast visual acuity. 100%, 25%, 10% and 5% contrast visual acuity under bright and dark backgrounds, and the pupil size for corresponding conditions were recorded. The relationship between contrast visual acuity and age, SE, pupil size under bright and dark backgrounds were analyzed. Multiple linear regression analysis was performed to determine the correlations between those variables. Main Outcome Measures Different contrast visual acuity, age, spherical equivalent, pupil size. Result At bright background, 100% contrast visual acuity was significantly correlated with spherical equivalent （t=2.551, P1=0.012, R2=0.043）, but not with age and pupil size（all P〉0.05）; and contrast visual acuity （25%, 10%, 5%） was significantly associated with pupil size （t1=-4.111, PI〈0.001, R21=0.123; t2=-g.434,/P2〈 0.001, R22=0.14; t3=-5.766, P3〈0.001, R23=0.216）, but not with age （all P〉0.05） and SE （all P〉0.05）. At dark background, 100%, 25% contrast visual acuity was significantly correlated with spherical equivalent （t1=2.695, P1=0.008, R2=0.057; t2=2.429, P2=0.017, R2= 0.047）, but not with age（all P〉0.05） and pupil size（all/〉0.05）; and contrast visual acuity （10%, 5%） was significantly associated with pupil size （t1=-2.305, P=0.023, R2=0.042; t2=-2.424, P2=0.017, R2=0.046）, but not with age （all P〉0.05） and SE （all P〉0.05）. Conclusion 100% contrast visual acuity was negatively correlated with SE under either bright or dark background, but no relationship with pupil size. While the 10%, 5% contrast visual acuity was negatively associated with pupil size. Under bright background, the effect of pupil size on visual acuity increased as the contrast reduced. The relationship between pupil size and 10%, 5% contrast visual acuities was less close under dark background than under bright background.