视觉矫正质量评价研究

Study of corrected visual performance and vision quality

目的 探讨视敏度和对比敏感度函数与视网膜光学成像质量的关系 ,评价各种屈光矫正方法获得的视觉质量。方法 2 3例近视眼患者 (4 1只眼 )近视度数范围为 - 1 2 5D～ - 9 2 5D ,散光度数 <0 5 0D ,每例患者用 3种方式全矫 :(1)同一品牌树脂镜片的框架眼镜 (spectacles,SP) ;(2 )同一品牌的软性角膜接触镜 (softcontactlens,SCL) ;(3)同一材料和设计硬性角膜接触镜 (rigidgas permeablelens ,RGP)。分别在全矫状态下进行远距和近距的LogMAR视敏度检测和对比敏感度函数检测。为了避免主观误差 ,3种矫正方式的先后顺序随机决定 ,所用的视力表和对比敏感度函数视力表为同一设计类型 ,但视标方向不同。结果 远距视力RGP矫正的视敏度明显好于SCL (P <0 0 0 1)和SP(P <0 0 5 ) ,SCL和SP矫正视力差异无显著意义 (P >0 0 5 )。在低频率点 (1 5及 3 0cpd) ,3种方式的对比敏感度函数差异无显著意义 ,在高频率点 (6 0、12 0及 18 0cpd)RGP对比敏感度函数曲线明显高于SCL和SP。结论 视力对比敏感度函数可以较好的表达矫正的视网膜光学成像质量 ;RGP相对于SCL及SP而言 ,可提供较好的视觉质量。

Objective The present study was designed to examine the visual acuity (VA) and contrast sensitivity function (CSF) under three refractive correction methods, the visual performance and vision quality under different correction methods were compared and analyzed. Methods Twenty three college students with myopia (41 eyes, myopia range: -1.25 D～9.25 D; astigmatism <0.50 D) were enrolled and fully corrected by three different methods: 1) spectacles with resin lens material (SP); 2) soft contact lens (SCL); 3) rigid gas-permeable lens (RGP). The distant and near LogMar VA and CSF were examined. To avoid the subjective bias, the correction procedure was randomly selected and the VA chart and CSF chart used had the same pattern but different letters′ organization or directions. Results The best corrected distant VA was significantly higher in RGP wearing eyes than those in the Soft-CL and SP wearing eyes (P<0.01 and P<0.05, respectively). No statistically significant difference was detected between the SP and SCL wearing eyes. There was no significant difference in the near VA among these three conditions, although the near VA in RGP group was slightly better than that in the SCL condition. There was no significant difference in CSF value at low spatial frequencies (1.5 cpd and 3 cpd) among these three conditions. However, at middle and high spatial frequencies (6 cpd, 12 cpd and 18 cpd), the RGP curve was the highest and followed by the SCL and SP curves. Conclusion RGP correction offers the best visual acuity quality for myopia subjects. The CSF assessment can be used as an indirect method to evaluate the quality of corrected retinal image.