Analysis of ocular structural parameters and higher-order aberrations in Chinese children with myopia

BACKGROUND Myopia and high myopia are global public health concerns.Patients with high myopia account for 0.5%-5.0%of the global population.AIM To examine diopters,axial length(AL),higher-order aberrations,and other ocular parameters in Chinese children with myopia,to analyze the influence of structural parameters associated with myopia on visual quality,and to provide a theoretical basis for the prevention and treatment of childhood myopia and high myopia.METHODS This study included 195 children aged 6–17 years with myopia.The AL was measured with an ultrasonic ophthalmic diagnostic instrument,and the aberrations,corneal curvature(minimum K1,maximum K2,and average Km),central corneal thickness,anterior chamber depth,and anterior chamber angle were measured using a Sirius three-dimensional anterior segment analyzer.Using a standard formula,the corneal radius of curvature R(337.3/Km)and AL/R values were obtained.RESULTS The diopter of high myopia compared with low-middle myopia was correlated with age and AL(r=-0.336,-0.405,P<0.001),and AL of high myopia was negatively correlated with K1,K2,and Km(r=-0.673,-0.661,and-0.680,respectively;P<0.001),and positively correlated with age and the anterior chamber depth(r=0.214 and 0.275,respectively;P<0.05).AL/R was more closely related to diopter than AL in children with myopia,and 94.4%of children with myopia had an AL/R of>3.00.CONCLUSION The ocular structural parameters of children change because of different diopters.AL/R is more specific and sensitive than AL in evaluating the refractive status of myopia in children.An AL/R of>3.00 may be used as a specific index of myopia in children.There are differences in AL/R between high myopia and low-middle myopia,which can be used for the classification of ametropia.The degree of myopia has a certain influence on higher-order aberrations.

Study on the Corneal Higher-Order Aberrations and Correlation in Patients with Different Degrees of Myopia Suitable for Wavefront-Guided FS-LASIK

Background: Individualized corneal refractive surgery requires an understanding of the basis of higher-order aberrations before surgery. To investigate the characteristics and distribution of anterior surface wavefront aberrations in patients suitable for corneal refractive surgery. Methods: A total of 121 myopic patients (121 eyes, 18 - 45 years old) who underwent corneal refractive surgery were recruited from January to May 2016 at Affiliated Hospital, Yanbian University. Patients were randomly selected by the Pentacam anterior segment analysis system with a spherical equivalent (SE) of -0.25 to -10.00 D. The corneal anterior aberrations (total higher-order aberration;spherical aberration;Coma;Trefoil) and Q and K values were detected, and a correlation analysis of the relevant parameters was carried out. Results: The root-mean-square (RMS) of the third to sixth order aberrations of the corneal anterior wavefront aberrations at a 6 mm analysis diameter showed a decreasing trend in patients suitable for the corneal refractive surgery, and the RMS of the third order aberrations accounted for 62.92% of the total HOAs. The coma ratio (coma/total cornea higher-order aberrations) was increased with the increasing diopters, while the spherical aberration ratio (spherical aberration/total cornea higher-order aberrations) was not changed. In addition, the spherical aberration was 0.203 ± 0.082 μm (range: 0.061 to 0.503 μm), and the Q30 was -0.19 ± 0.03 (range: -0.58 to 0.31). There were significant differences in the coma aberrations of preoperative corneal anterior surface (3, 1) between the low, middle and high myopia groups (P = 0.013). The spherical equivalent was positively correlated with the corneal coma of the anterior corneal surfaces (R =?-0.241, P = 0.009), and the Q value was positively correlated with the total higher-order aberrations (R = 0.326, P Conclusions: Individual wavefront aberrations on the anterior surfaces of the cornea are comparatively different, and the Zernike coefficients are related to the degree of myopia. Spherical aberrations are the most overriding aberrations of the cornea.

Effect of incision types for Artisan phakic intraocular lens implantation on ocular higher order aberrations

AIM： To evaluate the effect of incision types for Artisan phakic intraocular lens （PIOL） implantation on ocular higher-order aberrations （HOAs）.METHODS： A retrospective review was conducted of the patients who had undergone Artisan PIOL implantation for the correction of myopia and followed up for at least 6mo. Patients are classified into 2 groups considering the incision type： cornea group with patients undergone clear corneal incision; sclera group with patients undergone sclera tunnel incision. All patients with postoperative astigmatism of under 1 diopter （D） were included to minimize the effect of residual astigmatism on postoperative HOAs. Visual acuity, special equivalents, astigmatism, predictability （±1 D from target refraction）, HOAs （coma, trefoil, spherical aberration）, and corneal endothelial counts were analyzed preoperatively and 6mo postoperatively.RESULTS： At the postoperative 6mo, all patients of both groups achieved uncorrected visual acuity of 16/20 or better, and significantly decreased the spherical equivalents compared with preoperative values. The predictability of refractive correction was 96% in the former, and 94% in the latter. Unlike the sclera group, preoperative astigmatism decreased significantly in cornea group at postoperative 6mo. The HOAs increased significantly at postoperative 6mo compared to the preoperative values in both groups, and the root mean square （RMS） total and trefoil wavefront aberration of cornea group were significantly higher than those of sclera group.CONCLUSION： Although corneal incision significantly reduces preexisting astigmatism, the postoperative 6mo of total RMS and trefoil aberration change may deteriorate the visual quality after Artisan PIOL implantation.

Statistical analysis of ocular monochromatic aberrations in Chinese population for adaptive optics ophthalmoscope design

It is necessary to know the distribution of the Chinese eye's aberrations in clinical environment to guide high-resolution retinal imaging system design for large Chinese population application.We collected the monochromatic wave aberration of 332 healthy eyes and 344 diseased eyes in Chinese population across a 6.0-mm pupil.The aberration statistics of Chinese eyes including healthy eyes and diseased eyes were analyzed,and some differences of aberrations between the Chinese and European race were concluded.On this basis,the requirement for adaptive optics(AO)correction of the Chinese eye's monochromatic aberrations was analyzed.The result showed that a stroke of 20μm and ability to correct aberrations up to the 8th Zernike order were needed for reflective wavefront correctors to achieve near difraction-limited imaging in both groups for a reference wavelength of 550 nm and a pupil diameter of 6.0mm.To verify the:analysis mentioned above,an A0 floodillumination system was established,and high-resolution retinal imaging in vivo was achieved for Chinese eye including both healthy and diseased eyes.

Comparison of age-related changes between corneal and ocular aberration in young and mid-age myopic patients

AIM: To study the dynamic character of aberration between the cornea and the ocular with aging, and to evaluate the symmetry of the aberrations between right and left eye in order to supply the data for clinic to do the refractive surgery reasonably. METHODS: This is a comparative case series study. 82 normal cases (164 eyes) including 37 females (74 eyes) and 45 males (90 eyes) were recruited through the routine examinations,Topolyzer and wavefront analysis. The average age was 25.9 +/- 5.0 years old (range 18 to 49 years old), and the mean spherical equivalent (SE) is -3.82 +/- 2.21D (range -1.00 to -6.00D). The changes of aberrations regarding age, the relationship between anterior corneal and total aberrations were analyzed,as well as the symmetry between right and left eyes by using Zernike terms. RESULTS: The Z (3) (1), RMS3 of corneal aberrations, Z (3) (1), Z (4) (0) RMS3 and RMS4 of ocular aberrations had a positive correlation with age. The zernike terms both in corneal and whole eye were significantly correlated between right and left eyes. CONCLUSION: The corneal horizontal coma, ocular horizontal coma and ocular spherical aberrations become to increase at the age of more than 40 years old. The dynamic change of aberration with aging, balance between corneal and ocular, and the symmetric character between left eye and right eye should be designed carefully in the treatment nomogram before the refractive surgery.

Repeatability and reproducibility of corneal higher-order aberrations measurements after small incision lenticule extraction using the Scheimpfug-Placido topographer

Background:To evaluate the precision of corneal higher-order aberrations measurements after small incision lenticule extraction(SMILE)using the Sirius Scheimpfug-Placido topographer(CSO,Italy).Methods:Seventy-fve eyes from 75 postoperative subjects were included in this prospective study.Three consecutive corneal aberrometric measurements were obtained with the Scheimpfug-Placido topographer by two experienced operators to assess intra-and inter-observer reproducibility.The within-subject standard deviation(Sw),test-retest repeatability(TRT)and the intraclass correlation coefcient(ICC)were calculated.Results:For intraobserver repeatability of anterior and total corneal aberrations,all ICCs were more than 0.922,except for trefoil(0.722 to 0.768).The ICCs of total root mean square(RMS),coma Z(3,±1),and spherical aberration Z(4,0)were over 0.810 while higher-order RMS,trefoil Z(3,±3),and astigmatism II Z(4,±2)were below 0.634 for posterior corneal surface aberrations.All Sw values for all types of aberrations were equal to or below 0.07μm.Regarding interobserver reproducibility,all TRT values were no more than 0.12μm,0.05μm,and 0.11μm for anterior,posterior,and total corneal aberrations,respectively.The ICC values ranged from 0.875 to 0.989,from 0.686 to 0.976 and over 0.834 for anterior,posterior,and total corneal aberrations,respectively.Conclusions:The repeatability of measurements of anterior and total corneal aberrations with the Sirius system in corneas after SMILE surgery was high,except for trefoil.There was some variability in posterior corneal aberrometric measurements.High reproducibility of corneal aberrometric measurements was observed between measurements of both examiners,except for trefoil,with poor to moderate reproducibility.

Efficacy of custom-made soft keratoconus lenses on corneal aberrations and photic phenomena in patients with keratoconus:a corneal topography imaging based study

AIM:To evaluate the efficacy of custom-made soft keratoconus(KC)lenses on corneal aberrations and photic phenomena in two different optical zones in patients with KC.METHODS:Sixty eyes of 42 patients with KC were examined at baseline and after fitting HydroCone(Toris K)soft silicone hydrogel lenses.Best spectacle-corrected visual acuity(BSCVA)and contact lens-corrected visual acuity(CLCVA)were recorded.Lower-and higher-order corneal aberrations(LOAs and HOAs)were measured with and without Toris K lenses and compared in central 4.5 mm and 7 mm zones.Mesopic pupil diameter and subjective photic phenomena were also assessed.RESULTS:Mean CLCVA was significantly improved compared to BSCVA(P<0.0001).Corneal curvature and refractive measurements were found to be significantly reduced by the use of Toris K lenses,except for posterior corneal curvature values.In the 4.5 mm central optical zone,all wavefront aberrations decreased significantly after lens fitting(P<0.0001).In contrast,in the 7 mm(peripheral)optical zone,values for HOAs,spherical and residual aberrations,and optical path differences were increased,while LOAs,trefoil,and quadrifoil coefficients were decreased.The rate of photic phenomena was significantly higher in participants with a pupil size>6.00 mm(85.7%).CONCLUSION:Toris K lenses provide good visual results and a significant reduction in central corneal aberrations in patients with KC but could cause an increase in peripheral aberrations.This practical and nonsurgical approach appears to be an effective method for the visual management of KC.

Comparison of higher-order aberrations and contrast sensitivity between Tecnis Z9001 and CeeOn 911A intraocular lenses:a prospective randomized study

Background The advent of wavefront technology in the past five years has provided some insight into the optical outcomes of cataract surgery. The Tecnis Z9001 intraocular lens （Tecnis IOL, AMO） with a modified prolate anterior surface was claimed to reduce or even eliminate ocular spherical aberration to improve the visual quality. The purpose of this study was to determine whether Tecnis IOLs can improve the quality of vision as evaluated by measuring visual acuity, wavefront aberration, and contrast sensitivity. Methods In an intraindividual prospective study, 20 patients with bilateral cataract were randomly assigned to receive a modified prolate anterior surface IOL （Tecnis Z9001, AMO） in one eye and a biconvex spherical surface IOL （CeeOn 911A, AMO） in the other. After 3 months, the following were investigated： best corrected visual acuity, pupil diameter, photopic and mesopic contrast sensitivity, and wavefront aberration of the whole eye （ocular）, cornea, and internal plane. Results The differences in the best corrected visual acuity and pupil diameter between the two groups were not statistically significant. Negative 4th-order spherical aberration （Z4^0） was found in the Tecnis group, whereas positive Z4^0 found in the CeeOn group for the internal and ocular plane. Statistically significant differences were found at the ocular higher-aberrations between the two IOLs. Contrast sensitivity testing showed significantly better results in the Tecnis group at visual angles higher than 1.0 degree under photopic conditions and at visual angles higher than 1.6 degree under mesopic conditions both without glare and with glare in comparison with the CeeOn group. Conclusions The Tecnis Z9001 IOL with a modified prolate anterior surface produces negative spherical aberration and consequently reduces the higher-order aberrations in pseudophakic eyes. This leads to enhanced contrast sensitivity and improved functional vision compared to conventional spherical IOLs.

Laboratory evaluation of higher-order aberrations and light scattering in explanted opacified intraocular lenses

Background:Intraocular lens(IOL)calcification is a serious condition that can only be treated by removing the clouded lens.Since explantation bears the risk of complications,it is often deferred until the patient finds the symptoms intolerable.Usually,as the IOL opacifies,visual acuity is minimally affected early on.In this study,we assessed the impact of IOL opacification on optical quality.Methods:We analyzed ten opacified explanted IOLs(Oculentis GmbH).Wavefront aberrations were obtained with a SHSOphthalmic device(Optocraft GmbH),which features a Hartmann-Shack sensor.The root mean square(RMS)of higher-order aberrations(HOAs)was compared.The effect of calcification on image quality was assessed through the Strehl ratio(SR).We detected light scattering with a C-Quant(Oculus GmbH)and expressed it as a straylight parameter.Results:At 2 mm,3mm and 4 mm,the mean RMS(±standard deviation)was 0.033μm(±0.026μm),0.044μm(±0.027),and 0.087μm(±0.049),respectively.The mean SR value was 0.81±0.15 at 3 mm,with four IOLs showing a nearly diffraction-limited performance,but in two explants,opacification precluded reliable measurements.Increased straylight was found in all opacified IOLs with a mean value of 150.2±56.3 deg^(2)/sr at 3 mm.Conclusions:We demonstrated that IOL opacification induces HOAs.However,the RMS remained low,which resulted only in a slight reduction of the SR-derived optical quality.On the other hand,we found a severe straylight elevation in the opacified lenses,which may result in dysphotopsia,such as glare,and subjective complaints,despite good visual acuity.

Changes in higher-order aberrations after central corneal regularization-a comparative two-year analysis of a semi-automated topography-guided photorefractive keratectomy combined with corneal cross-linking

Background:The optical quality in progressive keratoconus deteriorates due to ectasia and distortion of the corneal shape and optics.While corneal cross-linking(CXL)aims at stopping disease progression,"CXL-Plus"combines CXL with excimer laser ablation to improve visual function.Central corneal regularization(CCR)represents a therapeutic excimer laser modality specifically designed to smoothen the ectatic corneal shape and to reduce higher-order aberrations(HOA).We set out to compare CXL-Plus,consisting of CXL combined with CCR,with CXL by itself for patients with progressive keratoconus.Methods:Retrospective 2-year matched group analysis of patients who either underwent CXL-Plus{n=28)or CXL as a sole procedure(n=28)for progressive keratoconus.Main outcome parameters were HOA,visual function and tomographic results 12 and 24 months postoperatively.Results:After 12 months,the total HOA root mean square wavefront error was reduced from 0.79±0.30 to 0.40±0.19 pm(CXL-Plus;P<0.0001)and changed from 0.71±0.28 to 0.73±0.36 pm(CXL;P=0.814).Uncorrected distance visual acuity improved from 0.70±0.35 to 0.36±0.29 logMAR(CXL-Plus;P=0.0002)and from 0.65±0.39 to 0.46±0.37 logMAR(CXL;P=0.067),translating to gains of three or more lines in 50%(CXL-Plus)and 36%(CXL)of patients.The steepest keratometry value(Kmax)regressed by 5.84 D(CXL-Plus;P<0.0001)and 0.66 D(CXL;P=0752).For none of the investigated parameters a statistically significant change could be shown between 12 and 24 months.Conclusions:CXL-Plus in the form of a CCR reduces HOA and Kmax more effectively than CXL as a sole procedure.

SMILE术后主导眼转变及对视觉质量的影响

目的:分析SMILE术后主导眼的转变情况及对视觉质量的影响。方法:前瞻性临床研究。选取2022-06/12在新疆医科大学第一附属医院行SMILE术矫正近视的患者140例280眼,根据术后3 mo内随访时卡洞法检查主导眼别转变情况分为转变组(46例92眼)和非转变组(94例188眼)。术前、术后1、3 mo,评估两组患者的裸眼视力(UCVA),采用屈光矫正者生活质量(QIRC)量表评估主观视觉质量,并检测全眼高阶像差评价客观视觉质量。结果:纳入患者SMILE术前主导眼为右眼105例,左眼35例,术后1 mo 46例患者主导眼发生转变,术后3 mo较术后1 mo无新发主导眼转变。术前、术后1、3 mo,转变组和非转变组患者UCVA、QIRC量表评分均无差异(P>0.05)。两组患者主导眼比较,术后3 mo转变组患者总高阶像差、球差显著高于非转变组(P=0.030、0.046);两组患者非主导眼比较,术后1 mo转变组患者三叶草像差显著高于非转变组(P=0.008)。术后1 mo,转变组患者双眼三叶草像差差值明显高于非转变组(P=0.022),余均无差异。结论:SMILE术后部分患者会发生主导眼的转变,但对主观视觉质量无显著影响,术后早期客观视觉质量下降可能是主导眼转变的相关因素。

自适应光学人眼像差调控及其应用

自适应光学技术能够对波前像差进行实时测量及调控。1997年,该技术被首次成功地应用于活体人眼像差的调控,并获得了接近衍射极限的高分辨力视网膜视细胞图像和传统低阶像差矫正无法达到的"超视力"。随后自适应光学技术在眼科学研究中得到迅速发展。就研究内容来看,该领域主要包括视网膜高分辨力成像和人眼像差操控与视功能研究两大方向。美国Rochester大学Williams教授和加利福利亚大学Roorda教授于2011年分别对视网膜高分辨力成像和人眼像差操控与视功能研究方向的研究作了非常全面的综述。1997年,光电所在国内率先开展人眼自适应光学技术及其应用研究,本文在简单介绍人眼自适应光学系统原理的基础上,报道了光电所在该领域近五年的主要研究进展。

用于人眼波前像差测量的照明系统设计

为了解决采用细平行光照明测量大像差人眼时测量精度下降的问题,设计了一种自动可调照明系统。照明光路中加入了一个位置可以自动调整的准直透镜,调整这个透镜的位置可以准确地改变照明光的光屈度,精密电控平移台可以对准直透镜的位置进行快速准确扫描定位。实验测量了模拟眼的像差,对细平行光照明系统和自动可调照明系统的实验结果进行了对比。结果显示,使用自动可调照明使传感器获得图像的峰值信噪比(PSNR)由5.72 dB提高到19.89 dB,对-5 m-1模拟眼测量的平均离焦也由-(4.285±0.208)m-1提高到-(5.041±0.157)m-1,表明使用自动可调照明系统提高了Hartmann-Shack传感器图像的信噪比,使测量结果更加准确。

不同亮度状态下人眼像差对双眼叠加作用的影响

利用双眼自适应光学(AO)视觉仿真器测量了两种不同亮度条件(1和100cd/m2)下人眼像差对双眼对比敏感度和双眼叠加作用的影响,并针对2c/d,8c/d和16c/d(周期每度)三种不同的信号空间频率进行了测试。实验结果表明,自适应光学像差矫正能够使得双眼对比敏感度函数呈现出各个测试频率上的整体升高。在两种亮度条件下,双眼对比敏感度收益与单眼相比均无统计上的显著差异(p>0.05)。在中高频范围(8c/d、16c/d),单双眼的AO像差矫正收益均随亮度的升高而升高。对于本文测试的三种信号频率,高亮度条件下的AO像差矫正对双眼叠加作用无显著影响,而在低亮度条件下,AO像差矫正使双眼叠加作用降低。本文为不同亮度下的双眼视觉信息处理机制提供了重要依据。

2mm微切口SMILE术后近视矫治眼高阶像差的变化

背景 飞秒激光小切口基质内透镜取出术（SMILE）已逐渐应用于临床,但术中切口大小不统一,2 mm微切口SMILE对术眼术后屈光度及像差的影响尚不清楚. 目的 研究2 mm微切口SMILE术后术眼屈光度和高阶像差（HOA）的变化,探讨术眼术前屈光度对术后HOA可能的影响.方法 采用系列病例观察的研究方法,选取2013年1-4月在天津市眼科医院行2 mm微切口SMILE的近视及近视散光患者31例55眼,测量患者术前及术后1周、1个月、6个月的裸眼视力（UCVA）、最佳矫正视力（BCVA）和球镜及柱镜度,评价SMILE的有效性、安全性、稳定性及可预测性,应用WaveScan波阵面像差仪测量术前及术后各时间点的HOA.采用重复测量单因素方差分析比较术前和术后各时间点的各HOA,不同时间点间两两比较采用LSD-t检验,采用Spearman秩相关分析评价术前球镜及柱镜度与术后各阶像差及总像差间的相关关系.结果 术后1周、1个月和6个月的有效性指数均为1.2,安全性指数分别为1.2、1.2和1.5.术后3个时间点的等效球镜度（SE）均为0.00D.术后1个月和6个月,分别有96.4％和97.8％的术眼达到预计矫治SE的±0.5 D以内,所有术眼均达到±1.0D以内.术后各时间点术眼垂直彗差（Z7）和球差（Z12）较术前均明显增大,差异均有统计学意义（Z7：t=9.668、10.607、9.772,均P＜0.001;Z12：t=-6.227、-6.923、-7.441,均P＜0.001）,但术后3个时间点之间Z7和Z12的差异均无统计学意义（均P＞0.05）.术眼术后各时间点3～6阶像差和总HOA较术前均明显增大,差异均有统计学意义（均P＜0.05）,而术后3个时间点间各阶像差的差异均无统计学意义（均P＞0.05）.术眼术后各时间点S3、S4、HOA与术前球镜度均呈正相关（均P＜0.05）,与术前柱镜度均呈负相关（均P＜0.05）.术后各时间点术眼Z7与术前球镜度呈负相关,与术前柱镜度呈正相关;Z12与术前球镜度呈正相关,而与术前柱镜度呈负相关（均P＜0.05）. 结论 2 mm微切口SMILE矫治近视及近视散光安全、有效,手术稳定性好,可预测性高,虽然术后Z7和Z12、各阶像差、总HOA均较术前增大,但术后不同时间点之间的HOA相对稳定,且与术前球镜及柱镜度存在相关关系.

眼内散射光的临床意义及测量方法的研究进展

眼内散射光是由于光线在人眼内发生散射，降低了物像在视网膜的对比度，从而影响了视觉质量的物理现象。眼内散射光是失能性眩光的主要原因，可以引起各种不适症状。正常人眼的散射光由角膜、虹膜、巩膜、晶状体及视网膜组成，当这些屈光介质出现混浊或病理变化时，都可能引起相应散射光的增加。虽然目前存在多种测量手段及测量参数，但是仍然缺乏对散射光测量过程的统一化及散射参数定义的标准化，需要进行更为深入和广泛的研究。就眼内散射光的基本概念、来源、临床意义以及各种测量方法的研究进展进行综述。

Hwey—Lan Liou模型眼复曲面人工晶状体偏心及旋转对成像质量的影响

背景 研究证实白内障囊外摘出联合Toric人工晶状体（IOL）植入术能够有效矫正角膜散光，改善患者的裸眼视力，但Toric IOL植入后可能因偏心及旋转造成IOL的位移误差，其对成像质量的影响与球面IOL有何不同值得关注和研究。 目的 评价Toric IOL的旋转和偏心对成像质量和波前像差的影响。 方法 将放在Hwey-Lan Liou模型眼中的SN60AT球面IOL和Toric IOL沿各自的子午线和不同轴位偏移，子午线间隔为5°，轴位偏离自中心沿0°～90°方向，偏心量分别是0.25、0.50和0.75 mm，Toric IOL在模型眼中模拟旋转5°和10°，评价和比较不同IOL偏心量和旋转度对成像质量及波前像差的影响。 结果 球面IOL与Toric IOL居中时各瞳孔直径下调制传递函数（MTF）曲线在各空间频率时都非常接近4 mm瞳孔直径条件下，偏心0.25 mm时SN60AT IOL 6 c/d和12 c/d的MTF值分别为0.581 087和0.411 960，T3 IOL分别为0.454 259和0.382 313，T4 IOL分别为0.426 020和0.360 490，T5 IOL分别为0.425 606和0.359 877。偏心0.50 mm时SN60AT IOL 6 c/d和12 c/d的MTF值分别为0.573 073和0.412 787，T3 IOL分别为0.450 943和0.379 481，T4 IOL分别为0.423 153和0.356 664，T5 IOL分别为0.422 881和0.356 230。偏心0.75 mm时SN60AT IOL 6 c/d和12 c/d的MTF值分别为0.560 038和0.413 624，T3 IOL分别为0.445 597和0.374 322，T4 IOL分别为0.418 522和0.350 087，T5 IOL分别为0.418 468和0.349 976。分别沿0°、5°、10°、90°子午线偏心时MTF值非常接近。球面IOL与Toric IOL的均方根值（RMS）随着偏心量的增加而递增，其中彗差的增加较为显著，T4 IOL偏心0.75 mm时慧差由居中时的0增加到C（3，－1）－0.049 79 μm、C（3，1）－0.037 59 μm；三叶草像差增加到C（3，3）0.005 72 μm、C（3，－3）0.004 64 μm，散光有少许增加。Toric IOL旋转角度由5°增大至10°时，高空间频率下的成像质量显著下降，Toric IOL旋转时的RMS的变化主要由散光引起，且高阶像差没有任何改变。 结论 Toric IOL对偏心的耐受性与球面IOL非常接近，Toric IOL偏心时的成像质量只受偏心量的影响。Toric IOL偏心主要带来彗差增加，而散光和三叶草像差增加较少；Toric IOL旋转主要引起散光增加，高阶像差并未发生改变。

近视散光眼高阶像差和视觉质量的关系

目的 :探索近视散光眼的高阶像差与对比敏感度的关系 ,为屈光手术中像差引导的个性化切削的个体筛选提供客观依据。方法 :随机选择近视屈光手术术前接受检查的6 6例 132眼 ,平均年龄为 (2 3.16± 4 .87)岁 (19～ 4 1岁 ) ,球性屈光度为 (- 6 .82± 1.38)D(- 3.715D～ - 9.32 5D) ;柱性屈光度为 (- 0 .71± 0 .5 1)D(- 0 .0 8D～ - 2 .85 5D)。用主觉法测量屈光度数 ,并用CSV 10 0 0对比敏感度表灯测试最佳矫正视力下的暗室对比敏感度值 ,用AllegrettoWavefrontAnalyz er波前像差分析仪测量其像差值。结果 :①球 柱像差对 18c/d频段的对比敏感度有影响 (r=- 0 .196 ,P =0 .0 2 5 ) ;彗差没有表现出与对比敏感度有关的任何相关性 (P >0 .0 5 )。②近视度数和球 柱像差相关性为r =- 0 .5 0 2 (P =0 .0 0 0 ) ,和收稿日期 :2 0 0 2 -10 -2 5 ;修回日期 :2 0 0 2 -11-10作者简介 :江扬子 ( 1975 -) ,女 ,浙江温州人 ,医学硕士。通信作者 :王勤美 (E -mail:wqm @mail.eye .ac .cn)。彗差相关性为r=- 0 .2 81(P =0 .0 0 1) ,散光度数和球 柱像差相关性为r=- 0 .2 4 1(P =0 .0 0 5 ) ,和彗差相关性为r=-0 .176 (P =0 .0 4 3)。结论 :屈光手术中对高度数的近视散光以及高球 柱像差者进行波前像差引导的个性化?

波前像差技术及其在屈光手术中的应用

介绍测量人眼像差的几种主要方法及其在屈光手术中的应用。以Hartmann Schack、TsherningorScheiner Smirnovtheories理论为基础的像差仪或像差镜能测量人眼屈光系统所有的像差 ,所得到的数据与屈光手术系统相结合后设计个性化切削方案 ,从而能提高PRK。

短期配戴软性角膜接触镜对人眼像差的影响

目的探讨短期配戴软性角膜接触镜对人眼像差的影响。方法对25例(50眼)青壮年近视志愿者(等值球镜:-0.50～-7.25D)统一同时配戴软性角膜接触镜1个月,测定摘镜后1个月内不同时间的像差变化,并与戴镜前比较。结果戴镜前和摘镜后不同时间,除RMS5以外的各阶像差、总像差、总高阶像差RMS值及主要像差系数(C6～C9、C12、C17、C18、C24)绝对值变化比较差异均无显著性(P>0.05);像差在摘镜后1周时增加倍率最高,且以RMS1、RMS4、RMS5为著,2周时明显降低,1个月时除RMS5、RMS6值有所增高外,余无明显变化;高阶像差系数变化以三阶变化明显,且以C7为最大;戴镜前和摘镜后不同时间的主导像差类型均以C7为主,且有72%主导像差类型发生变化,摘镜后不同时间的主导像差类型与戴镜前的一致率约为60%;中高度近视RMSg和RMS4值增加倍率高于低度组,而RMS2值降低;有散光组的RMSg、RMS2值摘镜后比戴镜前减少;日均戴镜时间长者像差增加倍率高。结论短期配戴软性角膜接触镜对人眼像差影响虽轻微但复杂,总体上可使总像差、高阶像差和各阶像差增加,且以彗差为著,但随摘镜时间延长而有所下降。屈光度、散光、日均戴镜时间对摘镜后像差有影响。