屈光参差对对比敏感度的影响

Clinical research on the impact of the amount of anisometropia on the contrast sensitivity function

目的探讨屈光参差的程度对对比敏感度的影响。方法随机选择双眼屈光参差但矫正视力≥1.0的患者38例(76眼),平均年龄(29.61±8.78)岁(19～53岁),等效球镜值为(-6.57±3.64)D(0.25～-14.50D),双眼度数相差(-3.67±2.40)D(-1.50～-12.00D)。按屈光参差的程度将患者分成两组:A组44眼,双眼度数相差≥3.00D;B组32眼,双眼度数相差<3.00D。使用Stereo Optical公司生产的OPTEC6500型眩光对比敏感度测试系统分别测试患者在最佳矫正视力下左右眼的对比敏感度。应用SPSS11.5统计软件对结果进行配对比较的秩和检验。结果A组患者屈光度高的一眼较另一眼在中高频空间频率的对比敏感度下降,在空间频率为6.0c/d、12.0c/d和18.0c/d时,低屈光度眼与高屈光度眼的对比敏感度差值分别为6.54、12.04和6.27,P值分别为0.017、0.001和0.006,差异有显著性;而在低空间频率(1.5c/d和3.0c/d),双眼的对比敏感度差值分别为3.54和5.41,P值分别为0.266和0.254,双眼间的对比敏感度差异无显著性。B组患者左右眼的对比敏感度在各个空间频率(1.5c/d、3.0c/d、6.0c/d、12.0c/d和18.0c/d)中低屈光度眼与高屈光度眼的对比敏感度差值分别为-1.24、5.75、3.00、2.32和3.00,差异均无显著性,P值分别为0.824、0.327、0.789、0.419和0.062。结论3.00D以上的屈光参差影响中高频空间频率的对比敏感度,3.00D以下的屈光参差不对对比敏感度产生明显影响。

Objective To discuss the impact of the amount of anisometropia on the contrast sensitivity function. Methods Thirtyeight patients （76 eyes） with anisometropia and corrected vision≥1.0 were divided into 2 groups （A and B）. The average age was （29.61±8.78）years （19-53 years）, mean spherical equivalent was （-6.57±3.64）D （0.25-14.50 D） and the differences between the left and right eyes were （-3.67±2.40） D （-1.50±12.00 D）. Group A was composed of 22 patients （44 eyes） whose intraocular differences were ≥3.00 D. Group B was composed of 16 patients （32 eyes） whose intraocular differences were 〈3.00 D. The patients＇ contrast sensitivity functions under the best corrected vision were tested with the Type OPTEC6500 glare and contrast sensitivity function testing system. The data was analyzed by the Wilcoxon rank sum test using SPSSll.5. Results In group A, statistically significant differences were found between the eyes with higher refractive errors and the contralateral eyes in the high and middle spatial frequencies. When spatial frequencies were 6,0 cycle/degree （c/d）, 12.0 c/d and 18.0 c/d, the differences between the eye with the lower refractive error and the eye with the higher refractive er- ror were 6.54, 12.04 and 6.27, respectively, and the P values were 0.017, 0.001 and 0.006, respectively. This was not found at the lower spatial frequencies. When spatial frequencies were 1.5 c/d and 3.0 c/d, the dispersion between the two eyes were 3.54 and 5.41, and the P values were 0.266 and 0.254. In group B, statistically significant differences were not found between the eyes with higher refractive errors and the contralateral eyes in the high, middle and low spatial frequencies. When spatial frequencies were 1.5 c/d, 3.0 c/d, 6.0 c/d, 12.0 c/d and 18.0 c/d, the differences between the eye with the lower refractive error and the eye with the higher refractive error were -1.24, 5.75, 3.00, 2.32 and 3.00, respectively, and the P values were 0.824, 0.327, 0389, 0.419 and 0.062, respectively. Conclusion If the amount of anisometropia is over 3.00 D, it will have an impact on the contrast sensitivity function at the high and middle spatial frequencies. Otherwise, anisometropia does not have an obvious impact on contrast sensitivity function.