准分子激光原位角膜磨镶术后屈光回退危险因素的Logistic回归分析

目的探讨准分子激光原位角膜磨镶术（LASIK）后屈光回退的危险因素。方法回顾分析2001至2004年在武汉同济医院眼屈光治疗中心接受LASIK手术的7537例患者资料．收集其巾屈光回退的病例298例（484眼）,按1：1病例对照研究方法选取相等例数非屈光回退病例作为对照组,两组的性别、手术时间等条件配比。收集两组病例的一般资料,如年龄、性别、家族史和服部相关检查结果（等效球镜度、最佳矫正视力、中央角膜厚度、切削直径等）等相关因素。应用SPSS13．0软件对两组的一般情况行）（。检验和t检验,对LASIK术后屈光回退的危险因素进行单因素和多因素条件Logistic回归分析。结果分析结果提示,有12个变量纳入多因素条件Logistic回归模型,有4个因素进入Logistic回归预测模型,其中年龄（OR=1．062,P=0．004）和等效球镜度（SE）（OR=3．747,P=0．001）是屈光回退的危险因素,而中央角膜厚度（CCT）（OR=0．475,P=0．002）和切削直径（LAD）（OR=0．982,P=0．000）是屈光回退的保护阁素。Logistic回归预测模型为：P=1／1＋Exp∑（-7．582—0．060AGE-1．321SE＋0．744LAD＋0．018CCT）,表示P值越大．术后越易发生屈光回退。判断术后屈光回退的灵敏度为79．54％,特异度为76．78％。结论年龄越大,屈光度越高和中央角膜厚度越薄者,术后越容易出现屈光回退。术中采用较大的激光切削直径将有助于提高LASIK的预测性,减少屈光回退的发生。本研究建立的Logistic回归模型能较好地预测术后屈光回退的发生概率。     

准分子激光原位角膜磨镶术后屈光回退的危险因素分析

目的 探讨准分子激光原位角膜磨镶术后屈光回退的危险因素。方法 225例近视患者分别在LASIK术前以及术后6个月进行Schirmer试验、泪膜破裂时间、角膜知觉、角膜厚度和角、结膜荧光素染色检查,并接受McMonnies干眼症状问卷调查。综合病史及治疗效果对结果作比较分析。结果 LASIK术后屈光回退和预矫正屈光度、较大的切削深度以及术后的干眼症状显著相关。术后发生干眼症的32例患者8例（25%）同时伴有屈光回退,而未发生干眼症的193例患者中仅18例（9．3％）伴有屈光回退,差异有极显著意义（P〈0．01）。结论 LASIK术后干眼症患者屈光回退的危险性增加。     

LASIK术后屈光回退的相关因素分析

屈光回退一般来说是指角膜屈光手术一段时间后,屈光力逐渐向术前同种屈光力转变,而术后早期的裸眼视力往往正常。屈光回退的发生与多方面因素有关,高度近视、术后角膜后表面前凸、高眼压、干眼等都可以导致屈光回退。本文对准分子激光原位角膜磨镶术术后屈光回退发生的相关因素作一综述。     

PRK与LASIK治疗高度近视的疗效比较

为比较准分子激光原位角膜磨镶术与准分子激光角膜切削术治疗高度近视的疗效，对２８８眼行ＰＲＫ手术及２９眼行ＬＡＳＩＫ手术，分别分为两组，观察１～１２月。结果：ＰＲＫ组术后一年裸视大于等于０５占７９４％，大于等于０８占６３２％，其中二组大于等于０５占５８３％，大于等于０８占３１６％。ＬＡＳＩＫ组术后一年裸视大于等于０５占６９２％，大于等于０８占５３１％，其中，二组大于等于０５占６６７％，大于等于０８占５０％。最佳矫正视力大于等于术前者ＰＲＫ组占９３７％，ＬＡＳＩＫ组占９２％。ＰＲＫ组角膜混浊一月时最重，一年时最轻。ＬＡＳＩＫ组无角膜混浊发生。实际矫正度在预计矫正度＋／－１Ｄ内者ＰＲＫ和ＬＡＳＩＫ分别占５２％和５１８％。结论：ＬＡＳＩＫ虽然由于微角膜切开刀的使用而较复杂，但对于大于－１００Ｄ的近视，是一种较ＰＲＫ好的手术方法。     

角膜地形图对准分子激光屈光性手术后屈光回退的预测作用

目的：建立根据角膜地形图前表面曲率变化预测准分子激光术后屈光回退的一种方法。方法：根据准分子激光术后327眼手术前后角膜地形图角膜前表面曲率变化值X与临床屈光度变化值Y得出两者关系Y＝0.0627X^2＋1.1534X,随访过程中根据X算出所矫屈光度,若预矫屈光度大于0.0627X^2＋1.1534X＋0.5,则作为屈光回退患者,与术后实际屈光回退情况进行比较。结果：随访观测309眼,实际屈光回退59眼,依本方法预测出回退的101眼中日后实际回退47眼,预测灵敏度79.66％,预测特异度78.40％。结论：角膜地形图在准分子激光术后屈光回退的预测中有一定的意义,可作为预测屈光回退的一种方法。     

PRK术的屈光回退行LASIK再手术的疗效观察

目的评价准分子激光角膜切削术(PRK)后屈光回退再行准分子激光原位角膜磨镶术(LASIK)的疗效.方法对PRK术后≥1年,屈光回退但屈光度稳定的患者9例(15眼),行LASIK再次手术矫正,随访观察半年.结果术中2眼角膜瓣游离,但无其它严重并发症.13眼术后6月达到术前最佳矫正视力.屈光度-1.00±0.58 D,比第一次手术后平均降低-4.25 D.结论PRK术后屈光回退行LASIK再手术是一种安全可行的方法,术后视力恢复快,屈光稳定.     

近视相关的多因素分析

目的了解与近视相关的多种因素对近视的综合影响程度。方法用多元逐步回归分析法对３９７眼ＰＲＫ术前的屈光状态，角膜地形图测得的角膜屈折力以及角膜多点厚度、眼轴长、晶体厚和前房深等测量值进行分析。结果眼轴、合并散光和年龄与近视度呈显著正相关，角膜垂直平均厚度呈显著负相关。近视＞８．０Ｄ者角膜中心厚度和垂直厚度显著薄于＜８．０者。有３个因素与之呈线性正相关：眼轴（Ｂ＝０．４７３），散光度（Ｂ＝０．３７６）和年龄（Ｂ＝０．０７０）。结论上述三因素应为近视手术的主要控制和观察指标。     

Effect of timolol maleate (0.5%) in the management of myopic regression post laser-assisted in-situ keratomileusis: Clinical and topographical outcomes

Purpose:The aim of this study was to analyze the effect of timolol maleate (0.5%) eye drops in the treatment of myopic regression after laser-assisted in-situ keratomileusis (LASIK).Methods:The study was conducted at a tertiary care eye hospital in north India between April 2017 & March 2018 as a prospective interventional study. Patients who underwent uneventful myopic LASIK with hansatome mechanical keratome and presented with regression were included in the study. Baseline demographic characteristics, time to presentation with regression best-corrected visual acuity (BCVA), refraction, intraocular pressure, central corneal thickness and keratometry were recorded at baseline and at each follow-up visit. The enrolled patients were prescribed timolol maleate (0.5%) eyedrops twice daily. They were followed up every month till 3 months on timolol maleate (0.5%) eyedrops and at 6 months post stopping the treatment.Results:Twenty-nine eyes of 15 patients were enrolled in the study. Mean pre LASIK spherical equivalent (SE) was – 7.48 ± 2.9 Diopters (Range-3.125 to –11.75 Diopters) and mean regression spherical equivalent was –1.02 ± 1.1 Diopters. There was a decrease in mean SE from presentation (intervention start point) up to 6 months follow-up (–1.34 ± 0.89 to –0.30 ± 0.29 Diopters). While posterior corneal curvature (K1 and K2 Back) changed significantly over treatment period (P = 0.0029, P = 0.0024 respectively), changes in anterior corneal curvature (K1 and K2 Front) were not significant (P = 0.05, P = 0.06 respectively). Central corneal thickness (CCT) and intraocular pressure (IOP) did not change significantly over treatment course.Conclusion:Timolol maleate (0.5%) eyedrop is an effective modality for the treatment of refractive regression post LASIK circumventing the need for laser re-treatment in such patients. The most probable mechanism is reversal of the anterior bowing of the cornea in response to intraocular pressure changes.     

31例视网膜母细胞瘤自发退行的临床组织病理学特点分析

目的探讨视网膜母细胞瘤自发退行的临床发生发展特点和组织病理学特点,为临床工作中该疾病的诊断和治疗提供参考。方法对31例视网膜母细胞瘤自发退行病例的临床和组织病理学资料进行回顾性分析。结果31例病例平均年龄25.06月,首发症状多为白瞳症(77.19%)、眼红(48.39%)和眼球变小(25.81%),病程为0.5月~4.5年,多出现类似青光眼发作、色素膜炎、眼内炎及发热等症状,最终自发退行,组织病理检查可见肿瘤灶内大片坏死、凋亡区及血管退行性改变,部分自发退行病灶中仍可见残存的肿瘤细胞。结论临床工作中应重视眼红、眼球变小等视网膜母细胞瘤的非典型表现,减少误诊;同时对视网膜母细胞瘤自发退行应密切随访观察。     

The use of correlation and regression methods in optometry

Correlation and regression are two of the statistical procedures most widely used by optometrists. However, these tests are often misused or interpreted incorrectly, leading to erroneous conclusions from clinical experiments. This review examines the major statistical tests concerned with correlation and regression that are most likely to arise in clinical investigations in optometry. First, the use, interpretation and limitations of Pearson's product moment correlation coefficient are described. Second, the least squares method of fitting a linear regression to data and for testing how well a regression line fits the data are described. Third, the problems of using linear regression methods in observational studies, if there are errors associated in measuring the independent variable and for predicting a new value of Y for a given X, are discussed. Finally, methods for testing whether a non‐linear relationship provides a better fit to the data and for comparing two or more regression lines are considered.     

Recurrent refractive error after myopic laser-assisted in situ keratomileusis – What could be the reason?

Recurrence of myopia after myopic LASIK reduces the outcome of the procedure. Important causes include post-LASIK ectasia, regression of myopia, accommodative strain, and lens or axial length changes. Herein, we present a case of myopia recurring after LASIK and try to arrive at the possible diagnosis among these, as the treatment differs for each. The detailed evaluation showed that our patient had regression of myopia after LASIK. Of the multiple causes for recurrence of refractive error after myopic laser vision correction, it is important to identify the relevant reason as the treatment and prognosis for each of these is different.     

干眼相关因素Logistic回归分析

目的:探讨各种眼表因素异常在干眼患者发病中的作用。方法:536例患者中,对其干眼症状及有关的眼表因素(泪液基础分泌、泪膜稳定性、角膜上皮完整性)检查结果量化后进行Logistic回归分析。结果:建立了以烧灼感(X3)、眼红(X4)、睫毛上有碎屑(X5)、晨起眼睑黏着(X6)、口干(X7)、流泪(X9)、视力波动(X12)、泪液基础分泌试验(X13)、泪膜破裂时间测定(X14)、角膜荧光素染色(X15)为变量的干眼发病Logistic回归预测方程:Y=-2.21+0.459X3+10.572X4-0.069X5+0.766X6+0.924X7+0.264X9-1.78X12+7.235X13+4.917X14+5.148X15;P=exp(Y)/[1+exp(Y)]。结论:干眼临床表现特征性明显,致病因素较多。可通过相关因素Logistic回归方程进行预测。     

Understanding and checking the assumptions of linear regression: a primer for medical researchers

Linear regression (LR) is a powerful statistical model when used correctly. Because the model is an approximation of the long‐term sequence of any event, it requires assumptions to be made about the data it represents in order to remain appropriate. However, these assumptions are often misunderstood. We present the basic assumptions used in the LR model and offer a simple methodology for checking if they are satisfied prior to its use. In doing so, we aim to increase the effectiveness and appropriateness of LR in clinical research.     

准分子激光原位角膜磨镶术后干眼和屈光回退的相关性(英文)

目的:探讨准分子激光原位角膜磨镶术后干眼和屈光回退的相关性。方法:近视患者225例分别在LASIK术前及术后6mo进行Schirmer试验、泪膜破裂时间、角膜知觉和角、结膜荧光素染色检查,并接受McMonnies问卷调查。综合病史及治疗效果对结果作比较分析。结果:LASIK术后干眼和屈光回退显著相关。术后发生干眼症的32例患者中8例(25.0%)同时伴有屈光回退,而未发生干眼症的193例患者中仅18例(9.3%)伴有屈光回退,差异有极显著意义(P<0.01)。结论:LASIK术后干眼患者屈光回退的危险性增加。     

准分子激光原位角膜磨镶术后屈光回退与术中角膜床厚度的关系

目的　探讨准分子激光原位角膜磨镶术（ｅｘｃｉｍｅｒ ｌａｓｅｒ ｉｎｓｉｔｕ ｋｅｒａｔｏｍｉｌｅｕｓｉｓ ＬＡＳＩＫ） 矫治高度近视后屈光回退与术中角膜床厚度的关系。方法　对４７６ 例９３８ 只眼在我院接受Ｌａｓｉｋ 治疗的患者中,发生屈光回退的病例９６ 例,１８９ 只眼与未发生屈光回退的病例３８０ 例７４９ 只眼术中角膜床厚度及术前、术后１ ｗ ｋ 、１ 、３ 、６ ｍ ｏ 屈光状态的资料进行对比分析。结果　有屈光回退眼组比无屈光回退眼组平均角膜床厚度小;屈光回退眼组屈光回退程度（ 术后６ ｍｏ 时） 与角膜床厚度呈负相关系,上述结果经统计学检验均有显著性差异（ Ｐ ＜ ００１） ;有屈光回退眼组术后早期（１ ｗｋ） 屈光状态略成过矫,但其后屈光回退程度在０ ．５ａ 内呈加重趋势。结论　高度近视准分子激光原位角膜磨镶术中的角膜床厚度是影响术后屈光稳定性的重要因素     

人眼视网膜母细胞瘤细胞凋亡的研究

目的 观察人视网膜母细胞（ｒｅｔｉｎｏｂｌａｓｔｏｍａ,ＲＢ）标本中细胞凋亡,探讨细胞凋亡在ＲＢ发生发展及消退中的作用。方法 用ＴＵＮＥＬ方法光镜和电镜观察人ＲＢ摘除眼球标本中是否存在细胞凋亡。结果 １５例人ＲＢ分化型和未分化型标本中有９例发现少量凋亡细胞,自发退化型ＲＢ中未发现凋亡细胞。每例中均见成片出现的坏死细胞。结论 视网膜母细胞瘤细胞死亡通过坏死与凋亡２种途径。细胞凋亡是ＲＢ自发退化的机制     

准分子激光上皮下角膜磨镶术后屈光回退的相关性分析

目的研究准分子激光上皮下角膜磨镶术(laser epithelial keratomileusis,or laser epithellal kemtoplas- ty,LASEK)术后出现屈光回退的各种可能的影响因素及其相关性。方法2003年12月至2004年8月在我院近视激光中心接受LASEK手术治疗的患者149例(278只眼),随访6～12个月。其中,发生屈光回退者15例(23只限),与余下的未发生屈光回退的患者的术前和术后资料进行对比分析。结果屈光回退率在中低度近视组为2. 56%,高度近视组6.25%,超高度近视组13.68%,三组比较差异有显著性(x~2=9.117,P＜0.05)。屈光回退组与未回退组比较,术前等效球镜、术中切削所占百分比差异有显著性(t=-2.815、-2.061,P＜0.05)。结论LASEK术后屈光回退的主要影响因素是术前等效球镜、术中切削所占百分比。     

近视LASIK术后屈光回退眼和非回退眼角膜形态改变的差异

目的　比较近视LASIK术后屈光回退眼和非回退眼角膜形态改变的差异,并评价这种差异在近视回退中的可能作用机制。 方法　近视回退组 15眼;非回退组 21眼。运用OrbscanⅡ系统分别在LASIK术前,术后 1周、1个月和3个月测量两组的角膜前 /后表面曲率半径和中央角膜厚度。 结果　两组术后的中央角膜厚度值都随着随访时间而增长,术后 1周值显著低于术后 1个月(P=0 000)和术后 3个月值(P=0 000)。但两组术后角膜前后表面的变化过程不一致,回退组角膜后表面曲率半径保持相对稳定(P>0 05),而术后 3个月前表面曲率显著凸于 1周值 (P=0 002);非回退组角膜后表面随时间而变扁平(P<0 05),而前表面曲率半径保持相对稳定 (P>0 05)。 结论　LASIK术后全角膜向前膨隆可能是近视回退的主要因素。     

Risk factors of regression and undercorrection in photorefractive keratectomy:a case-control study

AIM:To determine risk factors of regression and undercorrection following photorefractive keratectomy (PRK) in myopia or myopic astigmatism.METHODS: A case-control study was designed in which eyes with an indication for re-treatment (RT) were defined as cases; primary criteria for RT indication, as assessed at least 9mo postoperatively, included an uncorrected distance visual acuity (UDVA) of 20/30 or worse and a stable refraction for more than 3mo. Additional considerations included optical quality symptoms and significant higher order aberrations (HOAs). Controls were chosen from the same cohort of operated eyes which had complete post-operative follow up data beyond 9mo and did not need RT. The cohort included patients who had undergone PRK by the Tissue-Saving (TS) ablation profile of Technolas 217z100 excimer laser (Bausch & Lomb, Rochester, NY, USA). Mitomycin C had been used in all of the primary procedures.RESULTS:We had 70 case eyes and 158 control eyes, and they were comparable in terms of age, sex and follow-up time (P values:0.58, 1.00 and 0.89, respectively). Pre-operative spherical equivalent of more than -5.00 diopter (D), intended optical zone (OZ) diameter of less than 6.00 mm and ocular fixation instability during laser ablation were associated with RT indications (all P values <0.001). These factors maintained their significance in the multiple logistic regression model with odd ratios of 6.12, 6.71 and 7.89, respectively.CONCLUSION:Higher refractive correction (>-5.00 D), smaller OZ (<6.00 mm) and unstable fixation during laser ablation of PRK for myopia and myopic astigmatism were found to be strong predictors of undercorrection and regression.     

白内障超声乳化术后后囊膜混浊的多因素分析

目的 研究白内障超声乳化术后后囊膜混浊(PCO)的相关因素。方法 采用多因素logistic回归分析方法对可能引起PCO的诸多因素进行分析。结果 在120例经6～24个月临床随访的患者中，发现与PCO相关的因素是年龄、术后第1天前房反应和IOL类型，其它因素包括病人性别、核硬度、白内障类型、粘弹剂与PCO无关。结论 患者手术年龄越大、术后第1天前房反应越轻及选用丙烯酸酯类折叠式IOL有助于减少PCO的发生率。