期刊文献+
共找到6,241篇文章
< 1 2 250 >
每页显示 20 50 100
Influencing factor of the characterization and restoration of phase aberrations resulting from atmospheric turbulence based on Principal Component Analysis
1
作者 WANG Jiang-pu-zhen WANG Zhi-qiang +2 位作者 ZHANG Jing-hui QIAO Chun-hong FAN Cheng-yu 《中国光学(中英文)》 北大核心 2025年第4期899-907,共9页
Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high com... Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high computational complexity and insufficient capture of high-frequency phase aberration components,so we proposed a Principal-Component-Analysis-based method for representing phase aberrations.This paper discusses the factors influencing the accuracy of restoration,mainly including the sample space size and the sampling interval of D/r_(0),on the basis of characterizing phase aberrations by Principal Components(PCs).The experimental results show that a larger D/r_(0)sampling interval can ensure the generalization ability and robustness of the principal components in the case of a limited amount of original data,which can help to achieve high-precision deployment of the model in practical applications quickly.In the environment with relatively strong turbulence in the test set of D/r_(0)=24,the use of 34 terms of PCs can improve the corrected Strehl ratio(SR)from 0.007 to 0.1585,while the Strehl ratio of the light spot after restoration using 34 terms of ZPs is only 0.0215,demonstrating almost no correction effect.The results indicate that PCs can serve as a better alternative in representing and restoring the characteristics of atmospheric turbulence induced phase aberrations.These findings pave the way to use PCs of phase aberrations with fewer terms than traditional ZPs to achieve data dimensionality reduction,and offer a reference to accelerate and stabilize the model and deep learning based adaptive optics correction. 展开更多
关键词 phase aberration atmospheric turbulence principal component analysis Zernike polynomials
在线阅读 下载PDF
Corneal higher-order aberrations following small incision lenticule extraction for high myopic astigmatism correction
2
作者 Yin Liu Cheng Hu +3 位作者 Juan Yu Nian Xiang Bo Zeng Wen-Shan Jiang 《International Journal of Ophthalmology(English edition)》 2025年第7期1349-1356,共8页
AIM:To compare the visual outcomes and corneal higherorder aberrations(HOAs)of patients with high or low myopic astigmatism after small incision lenticule extraction(SMILE).METHODS:A total of 157 eyes of 157 patients ... AIM:To compare the visual outcomes and corneal higherorder aberrations(HOAs)of patients with high or low myopic astigmatism after small incision lenticule extraction(SMILE).METHODS:A total of 157 eyes of 157 patients who underwent SMILE were included in this retrospective,nonrandomized,comparative study.All the eyes which were with the rule astigmatism were divided into high astigmatism group(HAG;astigmatism≤-2.00 D,73 eyes)and low astigmatism group(LAG;astigmatism≥-1.00 D,84 eyes).Visual and refractive examinations were performed,HOAs of the anterior surface,posterior surface,and total cornea of the eyes were evaluated preoperatively and 6mo postoperatively.RESULTS:At the postoperative 6-month follow-up,uncorrected distance visual acuity of 20/20 or better was achieved in 97%and 100%eyes in HAG and LAG respectively and 74%and 100%eyes were within-0.50 D.Vector analysis revealed no significant differences in the correction index(P=0.066),angle of error(P=0.091)or flattening index(P=0.987)between two groups.The magnitude of error was-0.37±0.31 D in HAG and-0.04±0.19 D in LAG(P<0.001).Index of success(IOS)was 0.22±0.09 in the HAG and 0.50±0.46 in the LAG(P<0.001).HOAs of most anterior,posterior and total cornea significantly increased after SMILE,especially the spherical aberration and coma.For HAG,the SMILE procedure induced significantly higher anterior,posterior and total cornea horizontal coma and total corneal total HOAs compared with LAG(P<0.001)and these surgically induced HOAs predominantly originated from the anterior surface of the cornea.CONCLUSION:SMILE surgery induces more HOAs and a mild under-correction of astigmatism in eyes with high astigmatism.The increment in HOAs after SMILE is related to preoperative astigmatism. 展开更多
关键词 small incision lenticule extraction high astigmatism higher-order aberrations MYOPIA
原文传递
含偶次非球面的手机镜头降敏设计方法
3
作者 王洋 王楚文 顾志远 《光学精密工程》 北大核心 2026年第2期191-200,共10页
在光学设计过程中,光学系统性能的优化与公差分析是分隔开的,理论性能良好的系统公差可能过于严苛,因此,光学系统的降敏设计至关重要。手机镜头通常采用偶次非球面来降低系统的像差和总长,高次项的引入导致由光学表面的失调量引起的像... 在光学设计过程中,光学系统性能的优化与公差分析是分隔开的,理论性能良好的系统公差可能过于严苛,因此,光学系统的降敏设计至关重要。手机镜头通常采用偶次非球面来降低系统的像差和总长,高次项的引入导致由光学表面的失调量引起的像质退化比较严重。本文针对含有偶次非球面的手机镜头,提出了一种基于节点像差理论的降敏设计方法。首先,根据节点像差理论,分析了偶次非球面的圆锥曲面基底部分出现失调时,三阶彗差和像散的Zernike系数变化情况。随后,为了计算偶次非球面的高次项部分由失调引入的波像差变化量,通过光瞳坐标变换,获得了光学表面在失调状态下的光瞳图,并且根据光瞳的坐标变化对波像差变化量进行了计算;最后,建立了适用于含偶次非球面光学系统的实际性能模型,并且利用该模型设计了一个4片式手机镜头。公差分析结果表明:在5μm偏心和5′倾斜公差范围内,经过30 min的优化,手机镜头的RMS波像差均值相较于默认设计方法减少了33%,验证了本文提出的设计方法的有效性。 展开更多
关键词 节点像差理论 降敏设计 非球面 手机镜头
在线阅读 下载PDF
F9基因剪接位点共识区域中内含子突变造成的异常剪接模式研究
4
作者 马金 沈滟 +1 位作者 沈国民 高蒙 《南京医科大学学报(自然科学版)》 北大核心 2026年第1期55-67,共13页
目的:确定B型血友病致病基因F9的剪接位点共识序列,并筛选序列相关致病突变,以确定F9基因内含子中主要剪接调控位点。方法:从凝血因子Ⅸ(coagulation factorⅨ,FⅨ)突变数据库(FactorⅨVariant Database)中收集内含子突变,依据F9基因剪... 目的:确定B型血友病致病基因F9的剪接位点共识序列,并筛选序列相关致病突变,以确定F9基因内含子中主要剪接调控位点。方法:从凝血因子Ⅸ(coagulation factorⅨ,FⅨ)突变数据库(FactorⅨVariant Database)中收集内含子突变,依据F9基因剪接位点保守性分析筛选可能影响剪接的致病突变,重点关注患病人数多且致病效应强的突变位点所在区域,结合3种RNA剪接预测软件对突变导致的剪接效应进行预测。之后,采用微型基因剪接检测体系,对所选突变的剪接效应进行体外检测并通过变性毛细管电泳检测不同转录本所占比例,以明确各突变剪接效应的差异,进而确定F9基因剪接共识序列中影响剪接的关键位点。针对具有蛋白编码能力的异常剪接体,构建体外表达体系,通过Western blot及活化部分凝血活酶时间综合评估异常剪接体的胞内表达、胞外分泌及凝血活性状态。结果:序列与突变分析确定F9基因外显子4剪接位点附近的15个突变为靶突变,微型基因剪接实验证实其中14个突变可导致异常剪接,对比软件预测结果,进一步证实计算机预测具有局限性,不能准确预测具体剪接模式及其比例。证实了内含子上经典位点GT-AG的保守性,同时发现供体端+5G同样有利于剪接位点的正确识别,而相对保守的+7A则未对剪接位点识别产生重要作用,此外,模拟经典“AG”序列的深层内含子突变会造成剪接识别错位,显著提高异常剪接比例。蛋白表达与活性分析结果显示,p.D93-G125delinsG和p.G94-D131del两种异常剪接突变体的抗原合成及活性状态与野生型相比差异均有统计学意义(P<0.01)。结论:GT-AG是影响剪接调控的主要位点,F9基因内含子4剪接供体端非保守位点的+5G同样对剪接有调控作用。对不同突变造成剪接调控模式差异进行总结分析,可为大数据分析提供理论依据,并提高生物信息学预测的准确性。 展开更多
关键词 F9基因 内含子突变 剪接异常 B型血友病 致病机制
原文传递
MicroRNA aberrations:An emerging field for gallbladdercancer management 被引量:16
5
作者 Vishal Chandra Jong Joo Kim +1 位作者 Balraj Mittal Rajani Rai 《World Journal of Gastroenterology》 SCIE CAS 2016年第5期1787-1799,共13页
Gallbladder cancer(GBC) is infrequent but most lethal biliary tract malignancy characterized by an advanced stage diagnosis and poor survival rates attributed to absence of specific symptoms and effective treatment op... Gallbladder cancer(GBC) is infrequent but most lethal biliary tract malignancy characterized by an advanced stage diagnosis and poor survival rates attributed to absence of specific symptoms and effective treatment options. These necessitate development of early prognostic/predictive markers and novel therapeutic interventions. Micro RNAs(mi RNAs) are small, noncoding RNA molecules that play a key role in tumor biology by functioning like tumor suppressor- or oncogenes and their aberrant expression are associated with the pathogenesis of several neoplasms with overwhelming clinical implications. Since mi RNA signature is tissue specific, here, we focused on current data concerning the mi RNAs abberations in GBC pathogenesis. In GBC, mi RNAs with tumor suppressor activity(mi R-135-5p, mi R-335, mi R-34 a, mi R-26 a, mi R-146b-5p, Mir-218-5p, mi R-1, mi R-145, mir-130a) were found downregulated, while those with oncogenic property(mi R-20 a, mi R-182, mir-155) were upregulated. The expression profile of mi RNAs was significantly associated with GBC prognosis and prediction, and forced over-expression/ inhibition of these mi RNAs was shown to affect tumor growth and development. Further, differential expression of mi RNAs in the blood samples of GBC patients suggest mi RNAs as promising noninvasive biomarker. Thus, mi RNAs represent potential candidate for GBC management, though many hurdles need to be overcome before mi RNAs therapy can be clinically applied to GBC prevention and treatment. 展开更多
关键词 GALLBLADDER cancer MICRORNA aberrations Tumor SUPPRESSOR gene ONCOGENE BIOMARKER Therapy
暂未订购
ICL V4c植入术后视觉质量的研究进展
6
作者 祁云凯 汪洋合 +1 位作者 黄小娟 岳红云 《国际眼科杂志》 2026年第1期86-90,共5页
与其他屈光手术相比,有晶状体眼后房型人工晶状体(ICL)植入手术是目前屈光手术中最受欢迎的术式之一。ICL手术具有可逆性、高清视觉效果、不会改变角膜解剖结构等优点。目前临床最常用的是V4c型有中央孔型晶状体,围手术期不需要行虹膜... 与其他屈光手术相比,有晶状体眼后房型人工晶状体(ICL)植入手术是目前屈光手术中最受欢迎的术式之一。ICL手术具有可逆性、高清视觉效果、不会改变角膜解剖结构等优点。目前临床最常用的是V4c型有中央孔型晶状体,围手术期不需要行虹膜激光打孔术。且术后可获得良好的裸眼视力,然而,部分患者术后早期可能出现视觉干扰现象,如光晕、眩光等,尤其在暗光环境下可能影响视觉舒适度。文章针对ICL V4c术后高阶像差(HOA)、调制传递函数(MTF)、对比敏感度(CS)等视觉质量指标及影响因素进行综述,并探讨术后视觉质量可能存在的相对缺陷与相关机制。 展开更多
关键词 V4c型有晶状体眼后房型人工晶状体(ICL V4c) 视觉质量 高阶像差 调制传递函数 对比敏感度 影响因素
暂未订购
Comparison of correcting myopia and astigmatism with SMILE or FS-LASIK and postoperative higher-order aberrations 被引量:19
7
作者 Peng-Fei Zhao Ya-Bin Flu +3 位作者 Yue Wang Cai-Yun Fu Jing Zhang Chang-Bin Zhai 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2021年第4期523-528,共6页
AIM:To compare the effect of myopia and astigmatism correction and postoperative change in higher-order aberration as results of receiving small-incision lenticule extraction(SMILE)and femtosecond laser-assisted in si... AIM:To compare the effect of myopia and astigmatism correction and postoperative change in higher-order aberration as results of receiving small-incision lenticule extraction(SMILE)and femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:A prospective and non-randomized controlled study was conducted.The subjects are divided into two groups according to different operations received:229 eyes of 116 patients in the SMILE group and 168 eyes of 86 patients in the FS-LASIK group.All subjects were followed up for 3 mo by monitoring their uncorrected visual acuity(UCVA),best-corrected visual acuity(BCVA),spherical equivalent,higher-order aberrations,and the preoperative and postoperative complications.RESULTS:At 1 wk,1,and 3 mo post-surgery,224 eyes(97.8%),227 eyes(99.1%)and 229 eyes(100%)had UCVA≥20/20 in the SMILE group,while 165 eyes(98.2%),167 eyes(99.4%)and 167 eyes(99.4%)had UCVA≥20/20 in the FS-LASIK group,respectively(χ^(2)=0.146,2.135,and 1.124;all P>0.05).BCVA reduction was not observed in both groups at 1 and 3 mo of post-surgery(χ^(2)=0.734 and 1.898,P>0.05).There was no statistically significant difference in the spherical equivalent between the two groups at 1 and 3 mo post-surgery,though the percentage of the spherical equivalent within±0.50 D at 3 mo postsurgery was 98%in the SMILE group,which was higherthan that of the FS-LASIK group(92%,χ^(2)=1.872,P>0.05).The root mean square(RMS)values of total high-order aberration,coma,and spherical aberration of the two groups increased significantly in the early postoperative period and decreased after 3 mo,but the values were still higher than the preoperative levels(P<0.05);there was no significant difference between the two groups in the RMS values of total higher-order aberrations and specific higherorder aberrations(P>0.05).The incidence of complications in the SMILE group was lower than that in the FS-LASIK group(χ^(2)=14.52,P<0.05).CONCLUSION:SMILE and FS-LASIK can effectively treat myopia,significantly improve visual acuity,and increase the total high-order aberration,spherical aberration,and coma.The incidence of complications after SMILE is relatively low. 展开更多
关键词 MYOPIA femtosecond laser in situ keratomileusis small incision lenticule extraction high order aberrations
原文传递
Effects of higher-order aberrations on contrast sensitivity in normal eyes of a large myopic population 被引量:11
8
作者 Peng-Fei Zhao Shi-Ming Li +4 位作者 Jing Lu Hong-Min Song Jing Zhang Yue-Hua Zhou Ning-Li Wang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第9期1407-1411,共5页
AIM:To study the relation between higher-order aberrations(HOAs)and contrast sensitivity(CS)in normal eyes among a population of laser in situ keratomileusis(LASIK)candidates.METHODS:In 6629 eyes of 3315 LASIK... AIM:To study the relation between higher-order aberrations(HOAs)and contrast sensitivity(CS)in normal eyes among a population of laser in situ keratomileusis(LASIK)candidates.METHODS:In 6629 eyes of 3315 LASIK candidates,CS were measured under dark environment at the spatial frequencies of 1.5,3,6,12 and 18 cycles per degree(c/d),respectively,using an Optec 6500 visual function tester.Meanwhile,ocular HOAs were measured for a 6.0 mm pupil with a Hartmann-Shack wavefront analyzer.RESULTS:In the study,the subjects with an average spherical equivalent of-4.86±2.07 D were included.HOAs decreased from the third to the sixth order aberrations with predominant aberrations of third-order coma,trefoil and fourth-order spherical aberration.At low and moderate spatial frequencies,CS was negatively correlated with the third-order coma and trefoil aberrations,and decreased with increasing Z31,but increased with increasing Z3-3and Z5-1.At high spatial frequencies,CS decreased with increasing Z3-3and increased with increasing Z5-1.CONCLUSION:At a large pupil size of 6.0 mm,the thirdorder aberrations,but not the total aberrations,are the main factors affecting CS.Vertical coma is negatively correlated with CS. 展开更多
关键词 MYOPIA contrast sensitivity higher-orderaberrations COMA spherical aberration
原文传递
Comparison of two types of visual quality analyzer for the measurement of high order aberrations 被引量:9
9
作者 Jing Hao Lin Li +1 位作者 Fang Tian Hong Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第2期292-297,共6页
AIM: To compare the difference and agreement of KR- lW and iTrace for measurement of high order aberrations.METHODS: KR-1W and iTrace were respectively used in a group of healthy people (40 volunteers, 32 eyes) to... AIM: To compare the difference and agreement of KR- lW and iTrace for measurement of high order aberrations.METHODS: KR-1W and iTrace were respectively used in a group of healthy people (40 volunteers, 32 eyes) to measure the high order aberration (HOA) of corneal, internal and total ocular. The clinical difference and agreement of two instruments were respectively evaluated by paired-samples 1-test and Bland-Altman analysis. RESULTS: The paired-samples t-test showed that the corneal HOA measured by the two instruments had no statistical differences (P〉0.05); but the internal and total ocular HOA had significant statistical differences (P〈 0.05), and the mean results measured by iTrace were higher than that of KR-1W. However, Bland-Altman analysis revealed that the HOA of corneal and internal were all in 95% limits of agreement; and just one point of total ocular HOA was beyond the 95% limits of agreement. CONCLUSION: KR-1W and iTrace were consistent well in the measurement of corneal, internal and total ocular HOA, especially for the cornea. 展开更多
关键词 KR-IW iTrace high order aberration difference AGREEMENT
原文传递
Relationship between higher-order aberrations and myopia progression in schoolchildren: a retrospective study 被引量:8
10
作者 Ning Zhang Xu-Bo Yang +5 位作者 Wen-Qiu Zhang Long-Qian Liu Guang-Jing Dong Tao-Wen Chen Meng Liao Xuan Liao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2013年第3期295-299,共5页
AIM: To investigate the relationship between higher- order aberration (HOA) and myopic progression in schoolchildren. ·METHODS: Between April 23 2011 and August 29, 2011 in the children’s myopia outpatient clini... AIM: To investigate the relationship between higher- order aberration (HOA) and myopic progression in schoolchildren. ·METHODS: Between April 23 2011 and August 29, 2011 in the children’s myopia outpatient clinic of the West China Hospital of Sichuan University, 148 eyes of 74 schoolchildren were reviewed. HOAs for a 6 -mm pupil were measured with an aberrometer. Myopic progression rate was defined according to the change in spherical equivalent refraction (SER) divided by the time span (years). Subjects with myopic progression rate of ≥0.50 diopters (D) were classified as the ’fast’group and the subjects with myopic progression rate of 【0.50D were classified as the’slow’group. A retrospective study was conducted to compare HOA between the two groups, using root mean square (RMS) values and Zernike coefficients. ·RESULTS: The RMS values of HOA (t =2.316, P =0.02), HOA without Z 4 0 (t =2.224, P =0.03),third-order aberrations (t’ =2.62, P =0.01), and coma (t’ =2.49, P =0.01) were significantly higher in the fast group than those in the slow group. The individual Zernike coefficients of Z 3 -1 (t = -2.072, P =0.04) and Z 5 1 (Z =-2.627, P =0.01) displayed statistically significant differences between the two groups. Significant correlations were found between the RMS values of HOA (r =0.193, P =0.019), RMS values of HOA without Z 4 0 (r =0.23, P =0.005), RMS values of coma(r =0.235,P =0.004),RMS values of third-order aberrations (r =0.243, P =0.003), and the progression rate. · CONCLUSION: Our results provide evidence of a relationship between HOA and myopic progression. In a future prospective longitudinal study, we aim to verify whether HOA is a risk factor for myopic progression. 展开更多
关键词 ABERRATION MYOPIA CHILDREN disease progression refractive errors/etiology
原文传递
The correlation and overlaps between PD-L1 expression and classical genomic aberrations in Chinese lung adenocarcinoma patients: a single center case series 被引量:6
11
作者 Jianghua Wu Wei Sun +7 位作者 Haiyue Wang Xiaozheng Huang Xinyu Wang Weiyang Jiang Ling Jia Ping Wang Qin Feng Dongmei Lin 《Cancer Biology & Medicine》 SCIE CAS CSCD 2019年第4期811-821,共11页
Objective:To investigate the correlation and overlaps between PD-L1 expression and classical genomic aberrations in Chinese lung adenocarcinoma(LADC)patients.Methods:We reviewed 428 consecutive,surgically resected cas... Objective:To investigate the correlation and overlaps between PD-L1 expression and classical genomic aberrations in Chinese lung adenocarcinoma(LADC)patients.Methods:We reviewed 428 consecutive,surgically resected cases of LADC from October 2015 to December 2016 from our center.PD-L1 expression was evaluated based on tumor proportion score(TPS).Correlation and co-occurrence of PD-L1 expression level with those of classical driver genes,such as EGFR,ALK,ROS-1,and KRAS and with clinical variables and disease-free survival(DFS)were analyzed.Results:Seventy of the 428 cases(16.4%)showed TPS≥1%,and 21 cases(4.9%)showed TPS≥50%.PD-L1 positive expression was significantly associated with male gender,smoking,advanced TNM stage,and solid histologic subtype.Both TPS≥1% and ≥50%were correlated with the absence of an EGFR mutation(P<0.001)and the presence of ALK rearrangement(P=0.024).KRAS mutation was associated with TPS≥50%(P=0.035).PD-L1 positivity commonly overlapped with the alterations of classical driver oncogenes(58.5%with TPS≥1% and 42.9% with TPS≥50%).Approximately three-quarters of PD-L1 positive cases co-occurred with classical therapeutic-gene aberrations in cases with stage III/IV cancer or cancer progression.LADC could be divided into four subgroups based on the expression profile of current routine biomarkers for potential therapeutic strategies.Conclusions:PD-L1 expression is not only closely correlated with classic gene alterations but also commonly overlaps with the aberrations of classical driver oncogenes in Chinese LADC patients.These findings provide a useful overview of clinical strategies that rely on the profile of routinely used molecular biomarkers. 展开更多
关键词 Lung adenocarcinoma PD-L1 expression classical genomic aberrations molecular biomarkers
暂未订购
Antioxidants in aqueous extract of Myristica fragrans(Houtt.) suppress mitosis and cyclophosphamide-induced chromosomal aberrations in Allium cepa L.cells 被引量:4
12
作者 Akeem AKINBORO Kamaruzaman Bin MOHAMED +2 位作者 Mohd Zaini ASMAWI Shaida Fariza SULAIMAN Othman Ahmad SOFIMAN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第11期915-922,共8页
In this study, freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its co... In this study, freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions (A. cepa) were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-l-picrylhydrazyl (DPPH) free radicals' scavenging power of the extract was tested using butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as standards. Water extract of Myristica fragrans scavenged free radicals better than BHA, but worse than BHT. The extract alone, as well as in combination with CP suppressed cell division, and induced chromosomal aberrations that were insignificantly different from the negative control (P≤0.05). However, cytotoxic and mutagenic actions of CP were considerably suppressed. The observed effects on cell division and chromosomes of A. cepa may be principally connected to the antioxidant properties of the extract. The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M. fragrans as desirable properties of a promising anticancer agent. 展开更多
关键词 Allium cepa ANTIOXIDANTS Chromosomal aberration CYCLOPHOSPHAMIDE Mitotic index
原文传递
Comparative study of visual acuity and aberrations after intralase femtosecond LASIK:small corneal flap versus big corneal flap 被引量:4
13
作者 Ya-Li Zhang Lei Liu +5 位作者 Chang-Xia Cui Ming Hu Zhao-Na Li Li-Jun Cao Xiu-Hua Jing Guo-Ying Mu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2013年第5期641-645,共5页
AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 ey... AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error. 展开更多
关键词 femtosecond laser laser in situ keratomileusis refractive surgery FLAP visual acuity ABERRATION
原文传递
Analysis of ocular structural parameters and higher-order aberrations in Chinese children with myopia 被引量:5
14
作者 Xue Li Qi Hu +3 位作者 Qian-Ru Wang Zi-Qing Feng Fan Yang Chun-Yu Du 《World Journal of Clinical Cases》 SCIE 2021年第27期8035-8043,共9页
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 o... 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. 展开更多
关键词 MYOPIA Higher-order aberrations DIOPTER Axial length Cornea radius of curvature
暂未订购
Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa 被引量:3
15
作者 RAGUNATHAN Irulappan PANNEERSELVAM Natarajan 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第7期470-475,共6页
Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no repor... Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 μg/ml for 3 h and curcumin was given at 5, 10 and 20 μg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 μg/ml in Allium cepa root meristem cells. 展开更多
关键词 Chromosomal aberrations Sodium azide GENOTOXICITY Allium cepa
暂未订购
Ocular higher-order aberrations and mesopic pupil size in individuals screened for refractive surgery 被引量:3
16
作者 Seyed Javad Hashemian Mohammad Soleimani +4 位作者 Alireza Foroutan Mahmood Joshaghani Mohammad Jafar Ghaempanah Mohammad Ebrahim Jafari Mehdi Yaseri 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第2期222-225,共4页
AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. · METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 e... AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. · METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 eyes of 1 240 patients with myopia, myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, hyperopic astigmatism and compound hyperopic astigmatism using the Zywave aberrometer (Busch& Lomb). All patients had correctable refractive errors without a history of refractive surgery or underlying diseases. Root-mean-square values of HOAs, total spherical aberration, total coma and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥ 6.0 mm pupil, and pupil size measurements were performed under the mesopic condition. · RESULTS: The mean values of HOAs, total spherical aberration and total coma in the myopic group were 0.369 μm, ±0.233, 0.133±0.112μm and 0.330±0.188μm, respectively. In the hyperopic group the mean values of HOAs, total spherical aberration and total coma were 0.418μm±0.214, 0.202±0.209μm and 0.343±0.201μm, respectively. Hyperopes showed greater total HOAs (P <0.01) and total spherical aberration (P <0.01) compared to myopes. In age-matched analysis, only the amount of total spherical aberration was higher in the hyperopic group (P =0.05). Mesopic pupil size in the myopic group was larger (P ≤0.05). · CONCLUSION: The results suggested that significant levels of HOAs were found in both groups which are important for planning refractive surgeries on Iranians. There were significantly higher levels of total spherical aberration in hyperopes compared to myopes. Mesopic pupil size was larger in myopic group. 展开更多
关键词 corneal wavefront aberration PUPIL mesopic vision RACE MYOPIA HYPEROPIA
原文传递
Clinical study inpatient-reported outcomes after binocular implantation of aspheric intraocular lens of different negative spherical aberrations 被引量:3
17
作者 Ze-Quan Xu Xu-Hua Song +2 位作者 Wen-Zhe Li Yan Dou Qiang Wu 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2017年第7期771-774,共4页
Objective: To compare patient-reported outcomes after implantation of the ZA9003 intraocular lens(IOLs), or the MCX11 ASP IOLs or the spherical IOLs(HQ-201HEP). Methods: Prospective nonrandomized controlled trial was ... Objective: To compare patient-reported outcomes after implantation of the ZA9003 intraocular lens(IOLs), or the MCX11 ASP IOLs or the spherical IOLs(HQ-201HEP). Methods: Prospective nonrandomized controlled trial was used. A total of 105 patients(210 eyes) were divided into three groups according to the type of IOLs: ZA9003(35 patients, 70 eyes), MCX11 ASP(35 patients, 70 eyes) or HQ-201HEP(35 patients, 70 eyes). The main outcome was scores of Catquest nine-item short-form questionnaire. Additional outcome was best corrected visual acuities, spherical aberration(SA) and total higher-order aberrations(HOAs). Results: The global score was significantly lower in the spherical IOL group than the aspherical IOL group of-020 μm SA(P < 0.05) and the aspherical IOL group of-027 μm SA(P < 0.05), and no significant difference was found in the global score between the aspherical IOL group of-020 μm SA than the aspherical IOL group of-027 μm SA(P > 0.05). Significant differences were also found in question 2, question 5, question 6 and question 8 between the spherical IOLs and the aspherical IOLs. Conclusion: Implantation of an aspherical IOL could improve vision-related quality of life compared with a spherical IOL. However, there were no statistically significant differences in vision-related quality of life between aspheric IOLs with different negative spherical aberrations. 展开更多
关键词 Catquest nine-item short-form Patient-reported outcomes Vision-related quality Aspheric intraocular lens Spherical aberration
暂未订购
Evaluations of wavefront aberrations and corneal surface regularity in dry eye patients measured with OPD Scan Ⅲ 被引量:5
18
作者 Rong-Jun Liu Bai-Kai Ma +2 位作者 Yu-Fei Gao Yi-Yun Liu Hong Qi 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第3期407-412,共6页
AIM: To compare the wavefront aberrations and corneal surface regularity between dry eye(DE) patients and normal subjects and assess its diagnostic performance for DE measured with OPD Scan-Ⅲ.METHODS: Fifty right eye... AIM: To compare the wavefront aberrations and corneal surface regularity between dry eye(DE) patients and normal subjects and assess its diagnostic performance for DE measured with OPD Scan-Ⅲ.METHODS: Fifty right eyes of 50 DE patients and 31 right eyes of normal subjects were included.The examinations for ocular surface including logarithm of the minimum angle of resolution best-corrected distance visual acuity(logMAR BCVA) the ocular surface disease index(OSDI), tear film break-up time(TBUT) and corneal fluorescein staining(CFS).OPD Scan-Ⅲ was used to measure anterior corneal aberrations including total corneal aberrations, high order aberration(HOA), coma, trefoil, spherical aberration(SA), standard deviation of corneal power(SDP), surface regularity index(SRI) and surface asymmetry index(SAI).Statistical analysis were assessed with nonparametric tests and Spearman’s correlations.All parameters were also analyzed for sensitivity, specificity, and receiver operating characteristics(ROC) curves.RESULTS: Wavefront aberrations parameters including total corneal aberrations, HOA, coma, trefoil, and SA in DE group were significantly higher than those in normal group(P<0.001).Corneal surface regularity parameters including SRI and SAI in DE group were significantly higher than both in normal group(P<0.05).All the wavefront aberrations parameters had significant correlations with ocular surface parameters(P<0.05).The logMAR BCVA had positive correlations with SAI and SRI(all P<0.001).CFS scores had positive correlations with SAI and SRI(all P<0.001).All the wavefront aberrations parameters showed good diagnosis sensitivity and specificity, however, the corneal regularity parameters showed only good specificity but poor sensitivity.The cut-off value selected for trefoil in diagnosis DE showed the highest area under the curve(AUC, 0.921) values as compared to the other parameters with sensitivity of 0.955 and specificity of 0.867.CONCLUSION: Wavefront aberrations and corneal surface regularity are increased in DE patients and also correlated with ocular surface parameters.Wavefront aberrations parameters have potential to be indicators to diagnosis and monitor DE. 展开更多
关键词 dry eye wavefront aberration corneal surface regularity OPD ScanⅢ
原文传递
高度近视白内障患者术后人工晶状体偏心倾斜对高阶像差的影响
19
作者 梁堂钰 刘声统 吴小花 《国际眼科杂志》 2026年第2期320-323,共4页
目的:探讨高度近视白内障患者术后人工晶状体偏心倾斜对高阶像差(HOAs)的影响。方法:回顾性分析我院收治的高度近视白内障患者100例100眼,均给予超声乳化术+人工晶状体植入术治疗,术后3 mo进行随访,应用Pentacam三维眼前段分析仪测量人... 目的:探讨高度近视白内障患者术后人工晶状体偏心倾斜对高阶像差(HOAs)的影响。方法:回顾性分析我院收治的高度近视白内障患者100例100眼,均给予超声乳化术+人工晶状体植入术治疗,术后3 mo进行随访,应用Pentacam三维眼前段分析仪测量人工晶状体的倾斜度与偏心量,使用i Trace像差仪采集患者在3.0 mm与5.0 mm瞳孔下的HO As。采用Pearson线性分析人工晶状体偏心倾斜与HOAs的相关性。结果:患者术后人工晶状体的倾斜度为1.49°±0.32°,偏心量为0.33±0.05 mm,倾斜度与偏心量呈正相关。在瞳孔直径为3 mm或5 mm时,术后人工晶状体的倾斜度与总HOAs(r=0.351,P=0.003;r=0.287,P=0.015)、总彗差(r=0.389,P=0.002;r=0.332,P=0.005)成正相关性,而与总球差(r=0.382,P=0.235;r=0.149,P=0.207)无明显相关性。人工晶状体的偏心值与总HOAs(r=0.011,P=0.930;r=-0.146,P=0.215)、总彗差(r=0.023,P=0.856;r=-0.102,P=0.393)、总球差(r=0.085,P=0.476;r=-0.165,P=0.162)均无明显相关性。结论:高度近视白内障患者术后人工晶状体的倾斜会对总HOAs、总彗差造成影响,从而影响患者术后视力。 展开更多
关键词 高度近视 白内障 人工晶状体偏心倾斜 高阶像差
暂未订购
Measurement of the peripheral aberrations of human eyes:A comprehensive review 被引量:3
20
作者 Yanbo Zhao Fengzhou Fang 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2020年第2期53-68,共16页
It has been nearly 50 years since the first glimpse of the relationship between myopia and peripheral refractive errors. According to experiments on both animals and humans, the eyes with hyperopic peripheral vision a... It has been nearly 50 years since the first glimpse of the relationship between myopia and peripheral refractive errors. According to experiments on both animals and humans, the eyes with hyperopic peripheral vision appear to be at higher risk of developing myopia than those with myopic peripheral refractive errors. Despite the first measurement of peripheral refraction being achieved by a modified manual optometer, the concept of emmetropization triggered a rapidly increasing number of studies on peripheral aberrations. Not only the horizontal off-axis aberrations but also the meridional aberrations at different angles are measured by researchers during the development of peripheral aberrations measuring techniques. According to the differences among the working principles, a variety of techniques have been adopted for performing such measurements. The methods developed to realize the high-performance measurement involve the subject cooperating actively by rotating the head or eyes, the rotation of the whole optical path, and the combination of measurements of many light paths. This paper provides a review of the peripheral aberrations measuring techniques and their current status. This article also highlights the development trend of the measuring techniques of peripheral aberrations and practical applications of peripheral aberration measurements, such as the control of the accommodation, the measuring time, and the dynamic range problem of the wavefront sensor. Although wavefront sensing peripheral measurement is widely recognized for its capability to reveal both lower-order aberrations and higher-order aberrations, the efficiency of an autorefractometer is incomparable. The current study reveals that the most widely used peripheral aberration measurement methods are the use of an open field autorefractometer and Hartman-shack wavefront sensor-based techniques. 展开更多
关键词 Peripheral aberrations Myopia control Open field autorefractometer Hartman-shack wavefront sensor-based techniques
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部