The Related Study Of Wavefront Aberration Of Human Eyes With Different Vision Acuities

This thesis is about investigation of the features of wavefront Aberration and its factors of effect. Three different groups were involved in the study: emmetropic eyes, myopic eyes and myopic eyes after laser surgery(LASIK or LASEK). The feature of wavefront aberration of these groups and the related factors that may cause the differences were analized. This study may give some constructive suggestions on the application of custom ablation on laser surgery.The analyses of the feature of wavefront aberrations of emmetropic eyesPurpose: Wavefront aberrations of 175 young adults' eyes (average of age is 20.3, vision acuitiy is 1.5) were measured and studied in order to understand the feature of wavefront aberration of emmetropic eyes and its effect on the optical image.Methods: Wavefront aberration was measured using Spatially Resolved Refractometer (SRR). Data were transformed to coefficient of 35 terms of Zernike polynomials. Root mean Square (RMS) of eye wavefront errors were calculated from coefficient of these 35 terms. Results: In emmetropic eyes , the 3th term has the maximum value (0.6321±0.6722μm), the 26th term has the minimum value (0.0908±0.1007μm) and the values of all other terms are between these two. RMS value for total wavefront aberration is 0.5727±0.4209μm and the RMS value of high-order aberration is 0.4258±0.3753μm. RMS values of wavefront aberrations from 2nd order to 7th order are 0.3420±0.2890um, 0.2527±0.2357um, 0.1663±0.1244um, 0.1867±0.1670um, 0.1231±0.1069um, 0.1581±0.1795um, respectively.Conclusions: Among those emmetropic eyes of young male adult, the main effect of aberration is high-order aberration, which is also mainly affected by coma aberration,and the coma aberration is always lager than the spherical aberration. Meanwhile, astigmatism aberration, coma aberration and trefoil aberration are three main effects that influence the quality of the optics.The analyses of the feature of wavefront aberration of myopic eyes and Its factor of effectPurpose: Wavefront aberrations of myopic eyes( average of age is 23.6) were measured and studied in order to understand the feature of wavefront aberration of myopic eyes and its factor of effect,.Methods: Using the wavefront aberration of emmetropic eyes as control to study the features of wavefront aberration of myopic eyes. Multivariate Regression was used to analyse the factors that affect the high-order aberrations of myopic eyes, such as: sex, left or right eye, refractive power, corneal surface astigmatism power, intraocular astigmatism power, the surface asymmetry index (SAI), surface regularity index (SRI), eye axis and corneal thickness. Results: 1. In myopic eye, RMS value of total wavefront aberration is 0.7361±0.4782um and RMS values of high-order aberration is 0.3963±0.2484um. The RMS values for different order of aberration are: 0.5815±0.4622um, 0.2364±0.1524um, 0.1412±0.0943um, 0.1801±0.1382um, 0.1227±0.0952um, 0.1499±0.1129um, respectively. The RMS values of both total wavefront aberration and astigmatism aberration are larger than those values of emmetropic eyes (minimal t=3.108, p = 0.047).2. In myopic eyes, astigmatism aberration=－1.351－0.472×corneal astigmatism power－0.0853×intracular astigmatism power＋0.05474×eye asix and high order aberration = 0.210＋0.02597×refractive power＋0.288× SRI (minimal t = 1.995, p = 0.047).Conclusions: RMS value of total wavefront aberration of myopic eyes is larger than that of emmetropic eyes ,which is also mainly affected by astigmatism aberration. Corneal is the main effect that influences the aberration of myopic.The aberration increases along with the increasing of the corneal astigmatism power and SRI valueThe analyses of wavefront aberration in myopic eyes after laser surgeryPurpose: To understand the features of wavefront aberration after laser surgery and its factor of effect, especially the effect of different Lasersurgeries. Methods: Comparing the wavefront aberration of myopic eyes befo...