不同截囊方式所致晶状体后囊破裂的比较

目的　比较开罐式截囊与连续环形撕囊术中后囊破裂的原因和发生率。方法　将作者 4年来手术的 13 3眼白内障按时间顺序分为A组和B组。A组行开罐式截囊 ;B组行连续环形撕囊 ,其它步骤相同。分别统计后囊破裂的例数和原因。结果　后囊破裂共 14眼 ,其中A组 10眼 ,发生率 10 75 % ;B组 4眼 ,发生率 10 0 0 %。两组发生率的差异无显著意义 ( χ2=0 0 16,P >0 5 0 )。结论　后囊破裂与截囊方式无关。     

人工晶状体植入术后视网膜脱离的手术治疗

目的探讨人工晶状体植入术后视网膜脱离的手术方法并评价其疗效。方法2000年1月～2002年6月经玻璃体视网膜联合术治疗人工晶状体植入术后视网膜脱离31例(31眼)的临床资料作回顾分析。手术采取玻璃体切除、剥离视网膜前膜、激光封闭视网膜裂孔及眼内长效气体或硅油填充等方式。结果随访期为12～39月，平均22月。随访时视网膜复位29眼，占93．55％。有27眼(占87．11％)视力提高，其中≥0．1者22眼，最好视力为0．8。结论人工晶状体植入术后视网膜脱离使眼内病变复杂，易致严重PVR。应用玻璃体视网膜联合术，可使视网膜得以有效复位。     

少年儿童眼外伤术后无晶体眼的接触镜矫正

目的探讨少年儿童单眼外伤术后无晶状体眼的接触镜(CL)矫正方法和临床效果.方法观察81名少年儿童眼外伤术后患者的眼部改变,并根据其屈光状态的变化、对侧眼的状态及其生活的实际需要,选择验配了软性接触镜(SCL)、托力克软性接触镜(TSCL)、透气性硬性接触镜(RGPCL)、加虹膜色彩的非透气性硬性接触镜(PMMA虹彩片)和软、硬组合型镜片系统(Piggyback CL),并比较视力矫正效果.结果与对侧健眼比较,外伤术后眼角膜曲率半径值显著改变,角膜散光度明显增加.52眼选用SCL和TSCL,矫正视力与框架眼镜比较无明显差异;22眼选用RGPCL,4眼选用PMMA虹彩镜,3眼选用Piggyback CL,三种镜片矫正视力比框架眼镜明显提高.PMMA虹彩镜和Piggyback CL用于外伤后角膜白斑、术后无晶状体、虹膜严重损伤眼,除显著提高视力外,还明显改善了羞明症状和眼外观.结论在严格的医疗化管理下,利用CL矫正少儿眼外伤术后无晶状体眼的高度屈光不正、屈光参差,恢复双眼视觉是安全、有效的.硬性接触镜(HCL)的视力矫正效果明显优于SCL.     

儿童玻璃体切除术后无晶状体眼的二期人工晶体植入术

目的评价儿童玻璃体切除术后无晶状体眼二期人工晶体植入术的视力效果、手术技巧及其安全性.方法对32例儿童眼内炎玻璃体切除术后的无晶状体眼行人工晶状体植入术.采用颞下方平坦部巩膜灌注,行后房型人工晶体睫状沟缝线固定术,术后随访6～24月.结果所有患者均达到或超过术前最佳矫正视力,术后裸眼视力＜0.1者2眼,0.1～0.2者8眼,0.2～04者16眼,＞05者4眼.无严重远期并发症.结论儿童眼内炎玻璃体切除术后二期人工晶体睫状沟缝线固定术,手术效果可靠,术后并发症少,是矫正儿童无晶状体眼的理想手术方法.     

Pseudophakic accommodation with translation lenses – dual optic vs mono optic

PURPOSE: To investigate the pseudophakic accommodation effect in dual and mono optic translation accommodative intraocular lenses (AIOL) using linear matrix methods in the paraxial space. METHODS: Dual (anterior optic of power +32 D linked to a compensatory posterior optic of negative power) and mono lens power was determined in the non-accommodated state using linear geometric optics based on the Gullstrand model eye. The position of the AIOL was calculated from a regression formula. Pseudophakic accommodation was assessed with three systems: (1) forward shift of the mono optic lens, (2) anterior translation of the anterior optic in the dual optic lens system with an unchanged position of the posterior minus lens and (3) symmetrical anterior and posterior translation of the anterior and posterior lens. The Gullstrand model eye was modified by changing the axial length (and proportionally changing the phakic anterior chamber depth) to investigate the accommodative effect in myopic and hyperopic eyes. RESULTS: The dual optic lens system (2) yields a nearly constant accommodation amplitude of 2.4-2.5 D mm(-1) movement over the total range of axial lengths. The mono optic lens (1) provides a higher accommodative effect only in extremely short eyes (high refractive power of the lens), whereas for normal eyes (1.4-1.5 D mm(-1) movement) and for long (myopic) eyes the accommodative effect is much less than the dual optic lens. The dual optic lens system under condition (3) yields less accommodation amplitude compared with the dual optic system under condition (2) over the total range of axial length but provides higher accommodation amplitude compared with the mono optic lens system (1) with axial lengths greater than 22.3 mm (lens power 25.5 D). In the accommodated state, with lens translation of 1 mm, the absolute value of the lateral magnification increases with the refractive power of the mono optic lens (1) and decreases in both dual optic lens systems (under conditions 2 and 3). CONCLUSIONS: A mathematical strategy is presented for calculation of the accommodative effect of mono-optic and dual optic AIOL. The dual optic lens yielded a nearly constant accommodation amplitude of about 2.4-2.5 D mm(-1) translation, whereas the mono optic lens yielded an accommodative response of <2 D mm(-1) translation in long myopic or normal eyes. Only in extremely short eyes is the accommodative amplitude of the mono-optic lens higher than the dual optic lens.     

Non-compliance with lens care and maintenance in diabetic contact lens wearers

We hypothesize that diabetic contact lens wearers may represent a special group displaying higher levels of compliance with their lens care regimens as a result of learned behaviour relating to maintenance of their diabetic condition. To test this hypothesis, a prospective, single centre, controlled, masked study was performed whereby 29 diabetic contact lens patients and 29 non-diabetic control subjects were issued with disposable hydrogel contact lenses and a multipurpose lens care regimen. All participants were given identical instruction on lens care and maintenance. Compliance levels were assessed at a 12-month aftercare appointment by demonstration and questionnaire. Twenty-four different aspects of compliance were scored, 12 by observation and 12 by questionnaire report, of which only two showed a significant difference between the diabetic and control groups. Although the combined population of contact lens wearers was generally compliant, there were examples of non-compliance in both groups. Neither the duration of diabetes nor the degree of metabolic control appeared to have a significant effect on compliance. The results suggest that eye care practitioners cannot assume that diabetic patients will be more compliant with contact lens care and maintenance than non-diabetic patients.     

α‐crystallin: a review of its structure and function

α‐crystallin, the major protein of the mammalian lens in most species, is an aggregate assembled from two polypeptides, each with a molecular weight around 20,000 Da. It is polydisperse and can be isolated in a variety of forms, including spherical particles with molecular weights ranging upwards from about 200 kDa. Sequence comparisons reveal that it is a member of the small heat shock protein (shsp) family. These proteins are aggregates assembled from polypeptides of 10 to 25 kDa that share a common central domain of about 90 residues (the ‘α‐crystallin domain’) with variable N‐ and Gterminal extensions. α‐crystallin has been intensively studied for more than 50 years but its three‐dimensional structure remains unknown because it has not been possible to obtain crystals for X‐ray studies and it is too large for NMR measurements. Structural information has been derived from a variety of solution studies. Because of the protein's polydispersity, interpretation of data has been difficult. This led to different viewpoints and vigorous debate on its structure and properties. Recently, the crystal structures of two closely‐related small heat shock proteins have been determined. These have provided some insight into the structure of α‐crystallin and explanations of previous observations. Like many other heat shock proteins, α‐crystallin exhibits chaperone‐like properties, including the ability to prevent the precipitation of denatured proteins and to increase cellular tolerance to stress. It has been suggested that these functions are important for the maintenance of lens transparency and the prevention of cataract.     

生长因子对晶体上皮细胞生长影响的研究

目的 本研究通过对家兔晶体上皮细胞体外培养，探讨生长因子对其生长的影响。方法 将家兔晶体前囊经消化、离心，以获取分散的晶体上皮细胞，在DMEM培养基(含有10％小牛血清)中培养2周．经消化、传代。对培养的第二代晶体上皮细胞加入不同浓度的碱性成纤维细胞生长因子、表皮细胞生长因子、胰岛素样生长因子。培养1周后，用MTI、法检测其对晶体上皮细胞生长的影响。结果 体外培养晶体上皮细胞前二代晶体上皮细胞能保持较完整的上皮细胞形态及特性，第三代后部分细胞开始发生转化。碱性成纤维细胞生长因子、表皮细胞生长因子、胰岛素样生长因子．均能促进晶体上皮细胞的生长。结论 生长因子是引起后性白内障的一个重要因素。     

无缝线小切口白内障摘除人工晶体植入术临床分析

目的探讨无缝线小切口白内障摘除人工晶体植入术的疗效.方法对120例(142眼)老年性白内障行无缝线小切口白内障摘除人工晶体植入术,并与同期116例(136眼)现代囊外摘除人工晶体植入术对比.结果小切口组术后1周、2周、1个月裸眼视力≥0.5的眼数分别为106眼(74.64%),117眼(82.38%),130眼(91.54%),明显高于对照组(P<0.05).小切口术前平均角膜散光为(0.88±0.41)D,术后1周为(1.55±0.58)D,术后2周为(1.33±0.45)D,术后1个月为(1.08±0.46)D,手术前后差异无显著性(P>0.05).对照组术后平均角膜散光高于小切口组且差异有显著性.结论无缝线小切口白内障摘除人工晶体植入术具有手术创伤小、术后视力恢复快、术后散光小的优点,适合基层医院及防盲工作中运用.     

羟基喜树碱对培养兔晶状体上皮细胞的影响

目的研究羟基喜树碱(hydroxycamptothecine,HCPT)对培养兔晶状体上皮细胞(rabbitlens epithelial cells,RLECs)形态、增殖的影响及其机制,筛选防治后发性白内障的药物。方法首先进行RLECs体外培养,在第2、3代RLECs中加入HCPT,分别用光学显微镜和透射电镜观察细胞形态的变化。然后,在第2、3代RLECs中加入不同浓度的HCPT,观察HCPT对细胞增殖的影响。结果①HCPT对RLECs的形态具有显著的影响,透射电镜下主要表现为调亡细胞的形态改变。②HCPT能抑制细胞的增殖,其抑制作用随药物浓度增加、作用时间延长而增强。结论①HCPT通过凋亡机制引起体外培养RLECs的调亡。②HCPT能抑制体外培养RLECs的增殖,其抑制作用呈剂量依赖性和时间依赖性。③HCPT可能成为预防后发性白内障的药物。