微视野“固视稳定性”与视敏度相关性分析

A forensic study on the correlation between the fixation stability and visual acuity by microperimetry

目的探讨微视野检查中的"固视稳定性"与视敏度的相关性及其法医学价值。方法应用国际标准对数视力表对64名眼底损伤者进行视敏度检测,应用MP-1微视野仪行固视稳定性检查。将受检者按固视性质分为3组:固视稳定组、固视相对不稳定组、固视不稳定组;分别统计3组间视敏度的差异。结果①视敏度均值及标准差:稳定组为4.8±0.3;相对稳定组为4.4±0.3;不稳定组为4.0±0.16。单因素方差分析结果,F值19.244,P<0.05;提示3组间的视力水平存在统计学上的显著性差异。②视敏度与2°、4°范围固视百分率之间均有相关性,Pearson相关系数分别为0.631、0.732,P<0.05。③视敏度与2°、4°范围固视百分率之间均有线性关系,其一元线性回归方程分别为:Y=3.520+1.521X1;Y=2.487+2.389X2(Y为视敏度,X1、X2分别为2°、4°范围固视百分率)。结论微视野检查中的"固视稳定性"具有客观预估视敏度区间的法医临床学实用价值。

Objective To study the correlation between the fixation stability determined with MP-1 microperimeter and visual acuity, and to discuss its applicability in forensic medicine. Methods 64 subjects （64 eyes） with fundus injury were eveluated with international standard logarithmic visual acuity chart and fixation stabilities were determined with a MP-1 microperimeter. According to the fixation vision, the subjects were divided into 3 groups： stable fixtation （group A）, relative unstable fixation （group B ） and unstable fixation groups （group C ）. One-Way ANOVA was performed on the visual acuity among all the groups. Results （1） The visual acuities for three groups expressed as means ± standard deviation were 4. 8 ± 0. 3, 4.4 ± 0. 3, 4. 0 ±0. 16 respectively with F = 19. 244 （ P 〈 0.05 ）, suggesting significant difference in visual acuity among the three groups. （2） There were correlations between visual acuity and fixation percentage within 2° or 4°of the macular region, and the correlation coefficient was 0.631 and 0. 732 （P 〈 0. 05 ）, respectively. （3） There were linear relationships between visual acuity and fixation percentage within 2° or 4°of the macular region. The linear regression equations was respectively Y = 3.520 ＋ 1. 521X1 and Y = 2. 487 ＋ 2. 389X2 （Y as visual acuity,X1 as fixation percentage within 2°, and X2 as fixation percentage within 4°）. Conclusion The fixation stability determined by MP-1 microperimetry can be used for assessment on visual acuity objectively to some extent in forensic clinical medicine.