环曲面设计角膜塑形镜对角膜表面大高度差异近视患者的临床疗效探讨

目的探讨环曲面设计与普通设计角膜塑形镜对角膜表面大高度差异近视患者的疗效比较。方法方便选取该院2015年1月-2017年1月收治的40例80眼青少年近视患者为研究对象,根据佩戴不同设计角膜塑形镜分为两组,观察组(n=40)佩戴环曲面设计角膜塑形镜,对照组(n=40)佩戴普通设计角膜塑形镜,对比两组患者配戴角膜塑形镜前后裸眼视力和角膜3 mm治疗区散光以及治疗区偏心量。结果观察组患者配戴角膜塑形镜前和戴镜1周、1个月、3个月裸眼视力分别为(0.10±0.07)、(0.91±0.21)、(1.04±0.13)、(1.04±0.12);对照组分别为(0.10±0.70)、(0.90±0.23)、(1.02±0.19)、(1.02±0.17),两组对比差异无统计学意义(t=0.000 0、0.647 9、0.353 8、0.168 4,P>0.05)。观察组患者戴镜前和戴镜1周、1个月、3个月后3 mm治疗区散光分别为(2.12±0.57)、(0.79±0.47)、(0.62±0.32)、(0.69±0.20),对照组分别为(1.69±0.52)、(1.32±0.30)、(1.17±0.27)、(1.27±0.25),两组对比差异有统计学意义(t=3.940 8、6.721 3、9.288 7、12.810 1,P<0.05)。观察组患者戴镜1周、1个月、3个月后3 mm治疗区偏心量(0.75±0.31)、(0.64±0.22)、(0.56±0.16),对照组分别为(0.98±0.20)、(0.87±0.20)、(0.85±0.17);两组对比差异有统计学意义(t=4.408 4、5.470 0、8.783 8,P<0.05)。结论说明配戴环曲面设计角膜塑形镜可有效降低角膜表面大高度差异近视患者角膜散光,还可以获得良好的镜片稳定性,值得临床推广。

Profile and Character of Atmospheric Structure Constant of Refractive Index C_n^2

Random fluctuations of turbulence bring random fluctuations of the refractive index, making the atmosphere a random fluctuation medium that destroys the coherence of light-waves. Research in atmospheric turbulence is actually the investigation of the atmospheric refractive index. The atmospheric structure constant of refractive index, C n 2 , is an important parameter denoting atmospheric turbulence. In this paper, C n 2 is measured during the day and at night and in all four seasons using a high sensitivity micro-thermal meter QHTP-2. The vertical profile of C n 2 in Hefei (0-30 km) is investigated by the analysis of experimental data. The average profile of C n 2 in Hefei exhibits conspicuous day and night differences with increased altitude. The distribution of log(C n 2 ) is nearly normal and has conspicuous seasonal differences.