近视性屈光参差者的近视力

Study of reading visual acuity in myopic anisometropes

目的:通过两对比度标准对数近视力表和汉字近视力表研究近视性屈光参差者和非屈光参差性近视者近视力的特点。方法:屈光参差≥2.00D的近视性屈光参差者18例,非屈光参差性近视者17例,运用框架眼镜完全矫正的基础上,分别运用两对比度的标准对数近视力表和汉字近视力表进行近视力的测量及分析。结果:近视性屈光参差实验组和中低度近视对照组在100%和10%两种对比度下,实验组和对照组所测得的双眼近视力之间差异无统计学意义(P>0.05)。无论近视性屈光参差实验组,还是中低度近视对照组,100%对比度下所得近视力值与10%对比度所得值差异均有统计学意义(P<0.01)。无论是在100%对比度,还是在10%对比度下,汉字近视力表所测得的视力值均较标准对数近视力表所测得值显著低。在100%和10%两种对比度下的标准对数近视力表和汉字近视力表所测得的近视力,中度近视组和低度近视组两组间差异无统计学意义(P>0.05)。结论:近视性屈光参差者与中低度近视者双眼近视力无显著差异,但其近视力均受对比度影响,对比度降低,近视力下降。汉字视力表测得近视力值比标准对数视力表测得值显著低。

AIM：To study the characteristics of reading visual acuity in myopic anisometropes and myopes without anisometropia by E Standard Logarithm Near Visual Acuity Chart and Chinese Characters Near Visual Acuity Chart. METHODS：Eighteen myopic anisometropes（experimental group, EG）and seventeen myopes without anisometropia（control group, CG）were recruited for this study. All subjects were fully corrected based on subjective refraction using frame glasses and then were measured reading visual acuity by E Standard Logarithm Near Visual Acuity Chart and Chinese Characters Near Visual Acuity Chart. RESULTS：There was no significant difference in binocular reading visual acuity between EG and CG at contrast level 100% or 10%（P0.05）. The reading visual acuity measured at contrast level 100% was significant different from that measured under 10% in both EG and CG （P0.01）.The reading visual acuity measured by Chinese Characters Near Visual Acuity Chart was obviously worse than that measured by E Standard Logarithm Near Visual Acuity Chart at both two contrast levels （100%, 10%）. There was no significant difference in reading visual acuity between medium myopia group and low myopia group（P0.05）. CONCLUSION：There was no significant difference in binocular reading visual acuity between myopic anisometropes and myopes without anisometropia. The contrast had great effect on reading visual acuity. When the contrast was lower, the reading visual acuity measured was worse. There was no significant correlation between reading visual acuity and myopic diopter. The reading visual acuity measured by Chinese Characters Near Visual Acuity Chart was obviously worse than that measured by E Standard Logarithm Near Visual Acuity Chart. The reason might be that Chinese Characters Near Visual Acuity Chart only took the visual angle as standard design parameter according to the character＇s height, while ignored the complex configuration and stroke of characters. So the Chinese Characters Near Visual Acuity Chart used at present should perfect its design and conversion mechanism.