模糊适应对近视成人模糊阈值的影响

目的 研究近视成人对不同图片的模糊阈值在模糊适应前后的变化.方法 前瞻性自身对照研究.38例近视成人为实验组,屈光度-0.50～-6.00 D,散光度均＜-0.75 D,试镜架上放置等效球镜度数插片矫正至视力5.0以上.模糊阈值的测量由自主设计的电脑程序完成,依据double-staircase理论,随机呈现0～+2 D离焦量的3种图片(视力表E字母、Lena头像、街景图片).受检者在模糊适应前后均进行测量,判断图片“模糊”或“不模糊”.38例对象中有18例作为对照组隔天再次测量,测量方法一致但不进行模糊适应.数据采用重复测量方差分析处理.结果 ①对照组前后两次测量的模糊阈值差异无统计学意义.②实验组经模糊适应后模糊阈值降低,即模糊敏感性提高(E视标:F=5.883,P＜0.05;Lena:F=6.234,P＜0.05;街景图片:F=3.987,P＞0.05).③同一受检者在判断不同图片时的模糊阈值存在差异,Lena图像的阈值高于另2种图片(F=10.761,P＜0.01).结论 模糊适应能提高成人近视者对不同图片的模糊敏感性;模糊适应效应不只限于近视成人黄斑中心凹区;人眼对于不同图片的阈值存在显著差异.

Influence of blur adaptation on blur detection threshold among myopic adults

Objective To study the change in blur adaptation on blur detection thresholds (BDT) for different images in myopic adults.Methods This was a self-control prospective study.An experimental group of 38 myopic adults (SE:-0.50 D to-6.00 D with astigmatism ＜0.75 D,best corrected VA using trial frames was ＞5.0) participated in the study.BDT was measured using a double-staircase method for three different images (Tumbled Es,Lena,Street view),with an 0 to +2 D spherical defocus.Subjects were required to judge if the image looked "blurred" or "not blurred" before and after blur adaptation.A control group of 18 adults was measured in a similar way on another day but without blur adaptation.Data were analyzed using repeated-measures ANOVA.Results ①In the control group,no significant difference in BDT was observed between two subsequent measurements.②BDT in the experimental group decreased significantly after blur adaptation,i.e.,blur sensitivity to retinal defocus increased (Tumbled Es:F=5.883,P＜0.05;Lena:F=6.234,P＜0.05;Street view:F=3.987,P＞0.05).③ BDT of the Lena image was higher than for the other two images (F=10.761,P＜0.01).Conclusion After blur adaptation,blur sensitivity to different images improves.The blur adaptation effect was not limited to the foveal area.There was a significant difference in BDTs for different images.