屈光手术前严重视网膜病变的诊治和激光屈光手术的选择

目的:探讨激光屈光术前视网膜病变的及早诊断和处理方法及屈光手术方式的选择和疗效.方法:对预施准分子激光屈光手术的患者,扩瞳行三面镜检查,对有视网膜严重病变如裂孔伴格子样变性和囊样变性等的患者进行治疗,并随访后决定是否行屈光手术及选择何种术式.屈光术后随访24mo以上.结果:共检查648眼,52眼有视网膜裂孔及伴需处理的格子样变性或囊样变性区,占8.0%,有5眼因为视网膜病变严重,在处理眼底病变并随访后,未行准分子激光屈光手术.其余47眼在行激光处理视网膜病变后3wk以上,或冷凝手术3mo以后,查眼底原有视网膜裂孔牢固闭合、格子样变性囊样变性区激光光凝包绕确切并无新裂孔出现且视网膜无脱离,对其中26眼行LASEK手术、21眼行LASIK手术.结论:屈光手术不可忽视视网膜病变,应该将眼底的三面镜检查作为术前的常规检查项目.一旦发现格子样变性、囊样变性区和裂孔等病变,应及时采取预防性激光光凝等治疗,定期随访,如需行近视矫治手术应考虑手术的方法与时机.     

ZX-5及其光学异构体对兔眼血流和大鼠视网膜功能恢复的影响

目的:研究ZX-5对缺血后视网膜功能的恢复作用,并比较其光学异构体(R,R)-ZX-5和(S,S)-ZX-5对脉络膜血流及缺血后视网膜功能恢复的影响。方法:用彩色微球技术研究兔高眼压下(40mmHg)脉络膜血流的变化。用视网膜电生理仪测量b波,评价大鼠缺血后视网膜功能的恢复情况。结果:10g/L(R,R)-ZX-5滴眼液50μL能在不同时间点提高脉络膜血流(P<0.05),而(S,S)-ZX-5在相同条件下对提高脉络膜血流没有影响。ZX-5和(R,R)-ZX-5在不同时间点对视网膜缺血后功能恢复作用明显(P<0.05),(R,R)-ZX-5的作用优于ZX-5;而(S,S)-ZX-5对缺血后视网膜功能的恢复作用不明显。结论:ZX-5和(R,R)-ZX-5对增加脉络膜血流量和促进视网膜功能的恢复有显著功效,(R,R)-ZX-5恢复视网膜功能的作用更强,有可能进一步开发成有效防治眼血流障碍相关性眼病的药物。     

Ranibizumab治疗湿性AMD的相关研究

脉络膜新生血管(choroidal neovascularization,CNV)形成是湿性AMD导致视力丧失的重要因素。大量证据表明,血管内皮生长因子-A(vascular endothelial growth factor A,VEGF-A)是湿性AMD新生血管生成和血管渗漏的重要调质。VEGF的抑制剂已在临床中应用,其中,ranibizumab是一种重组的人源化抗VEGF单克隆抗体片段,能够结合并抑制VEGF,阻止血管渗漏和新生血管的形成,抑制CNV的发生。III期临床试验结果表明,ranibizumab不仅可以延缓患者视力的降低,同时相当一部分患者出现临床有意义视力提高。而且,在治疗过程中严重不良事件发生率低。ranibizumab很有可能首次使多数AMD患者获得良好而稳定的视力。2006-06-30ranibizumab经美国食品药物管理局批准应用于湿性AMD的治疗。本文简要回顾VEGF的生物学特点,临床应用的途径,同时对ranibizum-ab临床研究结果进行总结。     

免疫系统与青光眼

青光眼是一组以视神经凹陷性萎缩和视野缺陷为共同特征的疾病,病理性眼压增高是其主要危险因素。多种因素决定了青光眼视神经节细胞的最后结局。而免疫因素在青光眼的视网膜视神经损害中所起的作用应该是双重的。所以探明免疫系统在青光眼损伤修复中的作用,对青光眼的治疗具有重要的意义。     

光动力疗法治疗脉络膜新生血管性疾病的初步临床观察

目的:观察使用维替泊芬光动力疗法(photodynamic thera-py,PDT)治疗年龄相关性黄斑变性(age-related maculardegeneration,AMD)、病理性近视和特发性脉络膜新生血管(choroidal neovascularization,CNV)等3种主要的CNV相关疾病的临床效果。方法:对96例(109眼)经临床确诊的上述CNV患者进行PDT治疗,随访1～24(平均9.4)mo。采用最佳矫正视力、荧光素血管造影、吲哚青绿血管造影、光学相干断层成像等指标,观察治疗前后患者的视功能、CNV病灶大小及渗漏情况、以及视网膜水肿变化等,评价PDT治疗CNV的疗效。结果:本组病例包括AMD42例(54眼),病理性近视17例(18眼),特发性CNV患者37例(37眼)。AMD、病理性近视和特发性CNV的平均治疗次数分别为1.2,1.5和1.2次;视力稳定和提高者各组分别为83.3%,83.3%和86.5%;CNV渗漏停止或减少者各组分别为90.7%,83.3%和89.2%:视网膜水肿减轻者各组分别为77.8%,88.9%和86.5%。除3例AMD患者出现眼部严重不良反应外,未发现其他严重不良反应。结论:PDT可有效地改善或稳定AMD、病理性近视和特发性CNV患者的视功能,控制病变进展,近期随访结果安全有效。     

VEGF siRNA对兔眼碱烧伤后角膜新生血管的抑制作用

目的:研究血管内皮生长因子小干扰RNA(VEGF small in-terfering RNA,VEGF siRNA)对兔眼碱烧伤后角膜新生血管的抑制作用。方法:普通家兔25只以碱烧伤法(1mol/LNaOH溶液)诱导角膜新生血管(CNV)生成。碱烧伤后立即以脂质体(LF2000)为载体,右眼球结膜下注射VEGF siRNA重组质粒,左眼球结膜下注射pSilencer 2.1-U6 hygro空白质粒作为阴性对照。碱烧伤后1,3,5,7,14d,形态学分析评价角膜新生血管的生长情况。结果:与对照眼相比,碱烧伤后球结膜下注射VEGF siRNA重组质粒,实验眼在各时间段(3,5,7,14d),CNV长度明显变短,面积明显变小,差异有统计学意义(P<0.05)。结论:VEGF siRNA能有效地抑制碱烧伤后CNV的形成。     

补阳还五汤超声导入治疗缺血性脑卒中后上肢运动功能障碍临床研究

目的：观察补阳还五汤超声导入治疗缺血性脑卒中后上肢运动功能障碍气虚血瘀证的临床疗效。 方法：选取60例缺血性脑卒中后上肢运动功能障碍气虚血瘀证患者,采用随机数字表法分为对照组与治疗组, 每组30例。对照组给予内科与常规康复治疗,治疗组在对照组基础上给予补阳还五汤超声导入治疗。2组均治 疗8周。比较2组痉挛程度、上肢运动功能、生活质量及表面肌电信号指标。结果：治疗4周、8周后,2组改 良Ashworth量表分级均较治疗前改善,差异均有统计学意义（P＜0.05）;治疗组改良Ashworth量表分级改善情 况均优于同期对照组,差异均有统计学意义（P＜0.05）。组别和时间的交互作用对简式Fugl-Meyer运动功能评 定量表（FMA）、改良Barthel指数评定量表（MBI） 评分的影响均有统计学意义（P＜0.05）。组别因素对FMA、 MBI评分的单独效应均有统计学意义（P＜0.05）。时间因素对2组FMA、MBI评分的单独效应均有统计学意 义（P＜0.05）。治疗4周后,2组FMA、MBI评分均较治疗前升高,差异均有统计学意义（P＜0.05）。治疗8周 后,2组FMA、MBI评分均较治疗4周后升高,差异均有统计学意义（P＜0.05）。治疗4周、8周后,治疗组 FMA、MBI评分均高于同期对照组,差异均有统计学意义（P＜0.05）。治疗8周后,2组肱二头肌、肱三头肌 肌肉活动时的肌电均方根（RMS） 及积分肌电值（iEMG） 均较治疗前降低,治疗组上述4项上肢肌电信号指标 值均低于对照组,差异均有统计学意义（P＜0.05）。结论：补阳还五汤超声导入治疗缺血性脑卒中后上肢运动 功能障碍气虚血瘀证疗效满意,能有效降低上肢肌张力,缓解肌痉挛症状,改善患者的日常生活能力和运动 功能。     

Predictive modeling of 30-day readmission risk of diabetes patients by logistic regression,artificial neural network,and EasyEnsemble

Objective: To determine the most influential data features and to develop machine learning approaches that best predict hospital readmissions among patients with diabetes.Methods: In this retrospective cohort study, we surveyed patient statistics and performed feature analysis to identify the most influential data features associated with readmissions. Classification of all-cause, 30-day readmission outcomes were modeled using logistic regression, artificial neural network, and Easy Ensemble. F1 statistic, sensitivity, and positive predictive value were used to evaluate the model performance. Results: We identified 14 most influential data features(4 numeric features and 10 categorical features) and evaluated 3 machine learning models with numerous sampling methods(oversampling, undersampling, and hybrid techniques). The deep learning model offered no improvement over traditional models(logistic regression and Easy Ensemble) for predicting readmission, whereas the other two algorithms led to much smaller differences between the training and testing datasets.Conclusions: Machine learning approaches to record electronic health data offer a promising method for improving readmission prediction in patients with diabetes. But more work is needed to construct datasets with more clinical variables beyond the standard risk factors and to fine-tune and optimize machine learning models.     

Using machine learning to aid treatment decision and risk assessment for severe three-vessel coronary artery disease

BACKGROUNDThree-vessel disease (TVD) with a SYNergy between PCI with TAXus and cardiac surgery (SYNTAX) score of ≥ 23 is one of the most severe types of coronary artery disease. We aimed to take advantage of machine learning to help in decision-making and prognostic evaluation in such patients.METHODSWe analyzed 3786 patients who had TVD with a SYNTAX score of ≥ 23, had no history of previous revascularization, and underwent either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) after enrollment. The patients were randomly assigned to a training group and testing group. The C4.5 decision tree algorithm was applied in the training group, and all-cause death after a median follow-up of 6.6 years was regarded as the class label.RESULTSThe decision tree algorithm selected age and left ventricular end-diastolic diameter (LVEDD) as splitting features and divided the patients into three subgroups: subgroup 1 (age of ≤ 67 years and LVEDD of ≤ 53 mm), subgroup 2 (age of ≤ 67 years and LVEDD of > 53 mm), and subgroup 3 (age of > 67 years). PCI conferred a patient survival benefit over CABG in subgroup 2. There was no significant difference in the risk of all-cause death between PCI and CABG in subgroup 1 and subgroup 3 in both the training data and testing data. Among the total study population, the multivariable analysis revealed significant differences in the risk of all-cause death among patients in three subgroups.CONCLUSIONSThe combination of age and LVEDD identified by machine learning can contribute to decision-making and risk assessment of death in patients with severe TVD. The present results suggest that PCI is a better choice for young patients with severe TVD characterized by left ventricular dilation.

Coronary artery disease (CAD) is the leading cause of death and disability worldwide.^[1] Three-vessel disease (TVD) is the most severe form of CAD and is characterized by significant stenosis in all three major coronary arteries. The application of myocardial revascularization techniques, including coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), has significantly improved the clinical outcomes of patients with severe CAD. CABG has traditionally been the standard therapy for complex coronary lesions, including TVD.^[2] In recent years, with the advancements in PCI technology and the accumulation of operators’ experience, the incidence of periprocedural and long-term adverse events of PCI has substantially decreased, and PCI has been gradually applied in the treatment of TVD.^[3,4] Current guidelines recommend use of the SYNergy between PCI with TAXus and cardiac surgery (SYNTAX) score and diabetes status to guide the revascularization strategy for patients with TVD.^[5,6] Current practice guidelines do not recommend PCI for patients with TVD with a SYNTAX score of ≥ 23. However, using the SYNTAX score to guide clinical decision-making between PCI and CABG remains controversial, and its reasonability has been questioned since a newly published meta-analysis showed no significant association between the SYNTAX score and the comparative effectiveness of PCI and CABG.^[7] Moreover, the SYNTAX score is a quantitative indicator of the anatomical complexity of TVD and does not include clinical variables that may have significant effects on the patient’s prognosis. Whether some patients with specific clinical characteristics can obtain a comparable or even greater survival benefit from PCI than from CABG is unclear. Moreover, risk assessment for patients with TVD after revascularization therapy remain challenging.^[8–10]Machine learning has recently emerged as an important research method and has been successfully applied in many scientific fields, including clinical medicine.^[11–13] The decision tree algorithm, a common approach in machine learning, can handle non-linearity, heterogeneous effects, and high-dimensional features and partition a trial population into subgroups characterized by multiple simultaneous characteristics.^[14] In the present study involving a large cohort of patients with TVD with a SYNTAX score of ≥ 23, we employed a decision tree algorithm to generate specific subgroups, compared the long-term prognosis between patients who underwent PCI or CABG in each subgroup, and conducted a comparative analysis of the long-term prognosis between subgroups generated by machine learning. We evaluated whether machine learning can help in selecting the optimal revascularization method and assessing risk in patients with severe TVD.     

大鼠视网膜缺血再灌注后HIF-1α的表达与视网膜细胞凋亡的研究

目的:探讨大鼠视网膜细胞缺血再灌注后低氧诱导因子(HIF-1α)的表达、视网膜细胞凋亡的发生以及二者之间的关系.方法:采用前房灌注生理盐水升高大鼠眼压到110mmHg(1kPa=7.5mmHg)持续1 h的方法制作实验性视网膜缺血再灌注损伤模型,分别于再灌注不同时间点取材,行免疫组织化学法染色观察HIF-1α在视网膜细胞的阳性表达;采用DNA原位末端标记(terminal dUTP nick end labelling,TUNEL)法定位凋亡的视网膜细胞来检测视网膜凋亡细胞.结果:缺血再灌注2h组视网膜神经节细胞层及内核层细胞出现HIF-1α弱阳性表达,12h组阳性表达至高峰,24h组HIF-1α表达渐减少.视网膜组织细胞凋亡见于缺血再灌注12,24及48h组,凋亡细胞主要位于内核层,且24h组凋亡阳性表达最强.结论:缺血再灌注后大鼠视网膜HIF-1α的表达增加.参与视网膜缺血再灌注损伤;视网膜细胞的损伤部分以凋亡的形式发生,HIF-1α的表达可能与视网膜细胞凋亡有密切的关系.