模糊适应对模糊敏感性和对比度视力的影响研究

目的研究模糊适应对近视者与正视者眼模糊敏感性和LandoltC视力(100%和10%对比度)的影响以及近视者与正视者模糊敏感性和对比度视力(contrast Visual acuity,CVA)之间的差异。方法在双眼调节麻痹的情况下,通过远距屈光全矫基础上引入+2.00DS进行模糊适应30分钟。在模糊适应前后,采用Badal系统,通过5mm人工瞳孔控制瞳孔大小,分别测量20名近视者和15名正视者右眼的模糊敏感阈值、模糊分辨阈值;在模糊适应的过程中,每隔10分钟对高、低CVA进行一次测量。结果模糊适应后,近视者和正视者的高、低CVA均有显著性提高(P=0.000);近视者远模糊敏感阈值显著减小(t=2.282,P=0.034),正视者近模糊敏感阈值显著增加(t=2.703,P=0.019),主观焦深没有显著变化;近视组与正视组相比,近视组的远模糊敏感阈值、主观焦深和模糊分辨阈值均小于正视眼的各测量值(t=3.594,P=0.001;t=2.879,P=0.007;t=2.216,P=0.034)。结论人眼在离焦状态下适应一段时间后,近视者和正视者的高、低CVA均有显著提高;近视者较正视者对模糊察觉的敏感性增强。

Effect of blur adaptation on blur sensitivity and high-low contrast visual acuity

Objective To study the effect of blur adaptation on blur sensitivity and high-low contrast visual acuity between emmetropes and myopes.Methods Proximal and distal blur sensitivity thresholds and blur discrimination thresholds were measured under cycloplegia with a Badal system in 20 myopes and 13 emmetropes before and after adaptation to blur.Blur was induced by viewing through plus 2.00D spherical lenses worn over their distance refractive correction for 30 minutes.Landolt C visual acuity（100% and 10%） was measured during blur adaptation in every 10 minutes.Results A significant improvement in both high and low contrast Landolt C visual acuity was observed in both refractive groups（P=0.000）,and the improvements were statistically equivalent.Blur adaptation had a significant effect on distal blur sensitivity threshold for myopes（t=2.282,P=0.034） and on proximal sensitivity threshold for emmetropes（t=2.703,P=0.019）.The myopes had much smaller distal blur sensitivity thresholds,depth of focus and blur discrimination threshold compared with emmetropes（t=3.594,P=0.001;t=2.879,P=0.007;t=2.216,P=0.034）.A significant correlation was found between the distal blur sensitivity threshold and blur discrimination threshold（R=0.453,P=0.045）.Conclusion After blur adaptation,a significant improvement in visual acuity happens in both groups while the depth of focus has no change.Emmetropes are more sensitive to blur than myopes.