近视眼角膜前表面点扩散函数的斯特列尔比特征分析

Analysis of strehl ratio characteristics of the anterior corneal surface of myopic eyes

目的探讨不同瞳孔直径下近视眼角膜前表面总像差的斯特列尔比（SR）与总高阶像差SR的正常值及其与调制传递函数（MTF）的关系。方法横断面研究。应用Sirius3D角膜地形图仪对200例（400眼）进行角膜前表面总像差的SR和总高阶像差的SR检查。采用单因素方差分析比较角膜前表面总像差的SR和总高阶像差的SR分别在不同瞳孔直径下（3．0、5．0、6．0、7．0mm）的差异。Pearson相关分析研究二者分别与对应的均方根值（RMS）的相关性，以及总像差SR与对应的MTF值的之间的相关性。结果在不同瞳孔直径下（3．0、5．0、6．0、7．0mm）角膜前表面总像差100’SR值为（0．46±0．13）～（0．14±0．03）；总高阶像差100’SR值为（0．69±0．15）～（0．17±0．04）；角膜前表面总像差200’SR值为（0．45±0．13）～（0．16±0．04）；总高阶像差200’SR值为（0．70±0．15）～（0．20±0．05），各组均逐渐变小；角膜前表面总像差SR值和总高阶像差SR值与对应的RMS值之间均存在负相关关系。当瞳孔直径小时，总像差SR值与MTF值的高频区相关性较高；而当瞳孔直径大时，总像差SR值与MTF值的低频区相关性较高。结论近视眼角膜前表面总像差SR值和总高阶像差SR值与瞳孔直径呈负相关，并且SR值与RMS值及MTF值之间均存在一定的相关性。

Objective To study the normal strehl ratio （SR） values of total aberrations and the SR values of total higher order aberrations on the anterior corneal surface of myopic eyes with different pupil diameters; to study the relationship between SR values and the modulation transfer function （MTF）. Methods It was a cross-sectional study. The SR values of total aberrations and total higher order aberrations of the anterior corneal surfaces of 200 people （400 eyes） were examined with a SIRIUS 3D topography system. One-way ANOVA analysis was used to compare the SR values of total aberrations and total higher order aberrations of the anterior corneal surface for different pupil diameters （3.0, 5.0, 6.0, 7.0 mm）. A Pearson correlation analysis was used to study the relationship between the two types of SR values and the corresponding root mean square （RMS） values; and the relationship between SR values of the total aberrations and corresponding MTF values. Results The results for different pupil diameters （3.0, 5.0, 6.0, 7.0 mm） of the anterior corneal surface were as follows： the SR value of total aberrations 100＇ （0.46±0.13）-（0.14±0.03）; the SR value of total higher order aberrations 100＇ （0.69±0.15） -（0.17±0.04）; the SR value of total aberrations 200＇ （0.45±0.13）- （0.16±0.04）; and the SR value of total higher-order aberrations 200＇ （0.70±0.15）-（0.20±0.05）. The SR values of each group decreased with an increase in pupil diameter. The SR values of total aberrations and total higher-order aberrations on the anterior corneal surface were negatively correlated with the corresponding RMS values. When the pupil diameter was small, the SR value of total aberrations was more closely related to the higher frequency region of the MTF. When the pupil diameter was large, the SR value of total aberrations was more closely related to the lower frequency region of the MTF. Conclusion The SR values of total aberrations and total higher-order aberrations on the anterior corneal surface in myopic eyes are negatively correlated with pupil diameter. There is a certain correlation between SR values and the corresponding RMS and MTF values.