白内障激光乳化术后角膜组织的共焦显微镜观察

目的研究人白内障激光乳化手术后角膜各层组织的共焦显微镜下形态学改变。方法应用con-foscan 3.0共焦显微镜对Er:YAG激光乳化手术后1周~1月、无严重手术并发症的患者共10例(10只眼),进行扫描检查,记录和分析各层角膜组织图像。结果confoscan 3.0能够清楚地显示角膜的上皮细胞、基底层细胞、前弹力层、基质层细胞以及内皮细胞。激光乳化术后稳定的角膜同正常角膜的相应细胞在图像上没有显著差异,但有水肿的角膜在共焦显微镜下各层细胞均有明显改变。结论(1)confoscan 3.0共焦显微镜可以活体检查白内障激光乳化术后角膜组织结构和细胞的病理改变;(2)激光乳化作为一种新的白内障手术方式对角膜组织的损伤轻微;(3)活体共焦显微镜可以作为评价白内障手术后角膜组织改变的最佳检查。     

飞秒激光在深板层内皮角膜移植的应用前景

飞秒激光因其切割组织精密度高、对周围组织热损伤小,对角膜生物力学影响小被成功应用于LASIK手术中,但是越来越多的研究表明它可以完成其他角膜基质内手术,包括正受人们关注的深板层内皮角膜移植手术(deep lamellar endothelial keratoplast,DLEK),现就飞秒激光在DLEK手术中的应用前景作一综述。     

飞秒激光在晶状体手术中应用的研究进展

飞秒激光主要用于角膜屈光手术,近年来随着全飞秒激光技术的问世,角膜屈光手术发生了巨大的变革和发展。飞秒激光的光致分解作用可使人体组织发生电离,可在组织内进行精确切削,而对切削区以外的组织影响较小,具有极高的安全性。飞秒激光在白内障手术中的应用包括透明角膜切口的操作、晶状体前囊膜的切开、晶状体核的碎核等,在晶状体屈光手术方面主要用于老视眼的矫治。就近年来飞秒激光技术在白内障手术和晶状体屈光手术中的应用进行综述。     

飞秒激光在角膜手术中的应用

1990年代,一种新型的超短超快激光—飞秒激光(femtosecond laser,FS)出现并开始应用于各个领域。飞秒激光是一种以超短脉冲形式运转的近红外光。1飞秒等于千万亿分之一秒(1×10^-15s)。如此快的脉冲激光很少将热量和振动传导至周围组织,从而较少引起周围组织的损伤。随着技术的发展,开始出现应用飞秒激光制作角膜板层瓣,即飞秒激光辅助下的准分子激光角膜原位磨镶术,后来,其应用于飞秒激光辅助下的角膜移植术、角膜基质环植入术。飞秒激光进行角膜移植手术,主要是应用飞秒激光可以制作角膜植片和植床,准确切割各层病变角膜组织,即使在轻度的角膜斑翳和角膜水肿时,也可以达到部分切割的目的。     

积极而慎重地发展我国准分子激光屈光性角膜手术

积极而慎重地发展我国准分子激光屈光性角膜手术陈家祺八十年代出现的准分子激光角膜切削术，引起了屈光性角膜手术研究领域的一场革命。准分子激光手术不同于传统的角膜屈光手术，由于准分子激光属紫外激光，为单个光子且能量高，可直接打开组织分子中的共价键而无热效应...     

飞秒激光在眼科手术中的应用

飞秒激光具有切面平整、精准度高、损伤小及应用范围广等优点,其应用已成为近年眼屈光手术研究的热点.飞秒激光可以替代机械角膜刀,用于准分子激光角膜磨镶术制作角膜瓣,实施全程飞秒激光角膜屈光手术;还可用于老视、青光眼、白内障、角膜病等诸多方面的手术治疗.本文就飞秒激光的切削原理、临床应用以及研究进展作一综述.     

激光在治疗屈光不正及角膜疾病中的应用

角膜方面激光手术主要用于矫正屈光不正，其次是针对各种浅层角膜病变的治疗性角膜切除，以及角膜缘切开治疗青光眼等。由于角膜的光学性质所决定，角膜可以透过所有可见光，吸收红外和紫外波段的光线，因此角膜方面的激光冶疗只限于使不可见的红外或紫外波段的激光。红外激光有比：YAG、Na：YLF和Er：YAG激光等，用于角膜热成形术和角膜基质内切除术等；而紫外激光即准分子激光是目前角膜手术最常用的激光。随着激光技术的不断进步，必将给角膜激光带来飞速的发展。一、激光对角膜屈光手术的原理：近几十年来，人们在不断地探索角膜屈…     

角膜移植手术概况

角膜移植是利用异体的正常角膜组织取代混浊病变的角膜组织,使患眼复明或控制角膜病变的治疗手段.传统角膜移植分为穿透性角膜移植和板层角膜移植术,随着人们对角膜病认识程度的加深以及新技术新器材的使用,带角膜缘的板层移植联合中央部分穿透性角膜移植术、深板层角膜移植、深板层角膜内皮移植术、角膜缘移植等多种新的手术方式较之传统术式具有更好的光学效果,并大大减少了术后排斥反应、散光等并发症.此外准分子激光和飞秒激光的应用也使角膜移植术的手术效果更趋完美.同时,人工角膜移植手术为不适合传统穿透性角膜移植手术的患者提供一种新的选择.本文对准分子激光和飞秒激光应用于穿透性角膜移植、各种类型板层角膜移植以及人工角膜移植手术进行简要概述,并展望角膜移植手术的发展趋势.     

飞秒激光在治疗性角膜手术及晶状体手术中的应用

飞秒激光代表了目前屈光手术领域的最新技术．其新型扫描模式的屈光效应正在探索中。飞秒激光以其扫描的高精确度及安全性,已从单纯角膜屈光矫正向全方位治疗性应用方向转变,已被应用于穿透角膜移植、板层角膜移植、基质环隧道的制作以及辅助角膜胶原交联以治疗圆锥角膜,此外其在角膜缘移植和角膜活组织检查中的应用分别为眼表重建及角膜病理学诊断提供了新的手段,而飞秒激光辅助白内障手术及经晶状体矫正老视等方面的应用尚处于实验探索阶段。随着相关技术的日趋完善,飞秒激光的临床应用将更加广阔。就飞秒激光在治疗性角膜手术及晶状体手术中的应用进行综述。     

重视角膜生物力学特性在提高激光角膜屈光手术远期安全性中的作用

角膜激光近视手术在我国已开展近三十年,手术的临床效果良好,手术的稳定性、远期安全性更是一直被关注的焦点。角膜组织是一种典型的黏弹性组织,作为人眼重要的屈光介质,其生物力学特性是影响角膜屈光手术可预测性及稳定性的重要因素,涉及手术方式及设计、手术安全性及稳定性等多个方面。角膜生物力学特性的异常改变与角膜屈光术后发生角膜扩张、屈光回退密切相关。因此,重视角膜生物力学特性在角膜屈光手术中的作用,对于提高角膜屈光手术的安全性、有效性及可预测性十分重要。     

Strabisme Alternant - Etude clinique - traitement

The author defines motor and sensory alternation: the term alternation should not be used in isolation, it should always be accompanied by the name of the parameter concerned. Sensory alternation is always found together with motor alternation but the reverse is not true.The examining criteria for a diagnosis of sensory alternation are given, sensory alternation must not be confused with alternating inhibition. Working from clinical observations of cases of motor alternating strabismus, the author selects 2 types of binocular sensory relations which allow one to differentiate between:- cases of primary alternating strabismus- cases of secondary alternating strabismusThese forms will develop in different ways; in both cases a cure is possible providing that the right treatment is prescribed and once prescribed carefully followed, etc. It is always a case of serious forms of strabismus whose developmental period is spread over several years.According to the authors, the frequency of cases of true primary strabismus is from 1–3%, the frequency of cases of secondary alternating strabismus varies according to the type of therapy practised on cases of monocular strabismus with amblyopia. These latter will become cases of alternating strabismus under the influence of certain types of therapy carried out over several years (penalization, rocking, alternated occlusion, etc...).Experimental data on kittens confirm clinical data; kittens placed in abnormal environments during the sensitive period will show modification in the distribution of cortical cells and the absence of binocular cells (either because the excitation of the two eyes was not simultaneous, or not identical: artificial strabismus, occlusion, opaque glasses). This disturbances become irreversible after a certain period of exposure (a function of age, length of exposure, etc...).It is thus necessary to bear in mind: 1) the iatrogenic risks of certain orthoptic treatments, 2) the necessity for a binocular form of treatment as soon as possible, as once a certain stage is passed, cortical plasticity diminishes and the elaboration of normal binocular relations becomes impossible.

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Effects of Adenosine Agonists on Intraocular Pressure and Aqueous Humor Dynamics in Cynomolgus Monkeys

The effects of single or multiple topical doses of the relatively selective A₁adenosine receptor agonists (R)-phenylisopropyladenosine (R-PIA) and N⁶-cyclohexyladenosine (CHA) on intraocular pressure (IOP), aqueous humor flow (AHF) and outflow facility were investigated in ocular normotensive cynomolgus monkeys. IOP and AHF were determined, under ketamine anesthesia, by Goldmann applanation tonometry and fluorophotometry, respectively. Total outflow facility was determined by anterior chamber perfusion under pentobarbital anesthesia. A single unilateral topical application of R-PIA (20–250 μg) or CHA (20–500 μg) produced ocular hypertension (maximum rise=4.9 or 3.5 mmHg) within 30 min, followed by ocular hypotension (maximum fall=2.1 or 3.6 mmHg) from 2–6 hr. The relatively selective adenosine A₂antagonist 3,7-dimethyl-1-propargylxanthine (DMPX, 320 μg) inhibited the early hypertension, without influencing the hypotension. Neither 100 μg R-PIA nor 500 μg CHA clearly altered AHF. Total outflow facility was increased by 71% 3 hr after 100 μg R-PIA. In conclusion, the early ocular hypertension produced by topical adenosine agonists in cynomolgus monkeys is associated with the activation of adenosine A₂receptors, while the subsequent hypotension appears to be mediated by adenosine A₁receptors and results primarily from increased outflow facility.