正视及低中度、高度近视人群明暗环境对比敏感度分析

Contrast sensitivity of emmetropes and myopes in bright and dark circumstances

目的检测正视及低中度、高度近视3种不同人群在明、暗环境下的对比敏感度,评估其视功能状况。方法随机选取正视及低中度、高度近视患者各38例(最佳矫正视力均达20/20),分别以CGT-1000和MesotestⅡb对比敏感度仪测试明、暗环境下对比敏感度情况。结果明环境有眩光时,低中度近视及高度近视对比敏感度均低于正视眼(P<0.05);无眩光时,高度近视组对比敏感度低于其他2组(P<0.05),而正视与低中度近视无区别(P=0.087)。暗环境下,高度近视组对比敏感度低于其他2组(P<0.05),其余组间无差异。各组间无眩光情况下对比敏感度均优于眩光情况下对比敏感度。结论明、暗环境下,高度近视眼对比敏感度均低于正视眼,低中度近视界于二者之间。分析高阶像差、近视眼底退行性改变以及戴镜使物像缩小等可能是高度近视眼对比敏感度下降的原因。

Objective To investigate the contrast sensitivity of emmetropia, low or moderate myopia and high myopia patients in bright and dark circmnstances,and then evaluate its visual function. Methods Three groups were divided according to power of refraction （ emmetropia, low or moderate myopia and high myopia）,38 cases in each group. CGT-1000 and Mesotest Ⅱb were used to test contrast sensitivi- ty in bright and dark circmnstances. Results In bright and glare conditions, the contrast sensitivity of myopia were lower than emmetropia （ P 〈 0.05 ） ; While in bright and no glare conditions, the contrast sensitivity of high myopia group was lower than both emmetropia and low or moderate myopia group （P 〈 0. 05 ）, no significant differences was found between emmetropia and low or moderate myopia （ P = 0.087 ）. In dark circumstances, the contrast sensitivity of high myopia group was lower than the other two groups（P 〈 0. 05）. The contrast sensitivity under glare was lower than that of no glare in each group. Conclusions Both in dark and bright circumstances, the sequence of contrast sensitivity from high to low was emmetropia group, low or moderate myopia group, and high myopia group. High-order aberrations, fimdus retro- gressive changes and image miniflcation may be the reason to lower contrast sensitivity in high myopia patients. [ Rec Adv Ophthalmol 2008 ;28 （8） ：604-606,6091