儿童角膜穿孔伤修补及白内障摘出联合人工晶状体植入术

目的　探讨儿童角膜穿孔伤修补及白内障摘出联合人工晶状体植入术的临床疗效。方法　对３２ 例角膜穿孔伤、晶状体异物及外伤性白内障眼施行角膜穿孔伤修补、晶状体异物及白内障摘出联合人工晶状体植入术。结果　术前所有病例视力为光感～０．０２,而术后视力０．５～１．２者２０例,０．４、０．３、０．２ 及≤０．１ 者各３例。　结论　联合手术是儿童角膜穿孔伤、晶状体异物及外伤性白内障恢复视力的最好方法。     

儿童穿透性角膜移植联合白内障手术临床研究

目的观察儿童穿透性角膜移植联合白内障摘出及人工晶状体植入三联手术的临床效果。方法本组角膜穿孔伤后角膜白斑合并外伤性白内障12例(13眼),化学烧伤致角膜穿孔合并白内障5例(6眼),真菌性角膜溃疡穿孔合并白内障2例(2眼),共计19例(21眼),采用三联手术治疗,术后随访1~4年。结果术后角膜透明率85.71%(18眼),排斥反应发生率23.81%(5眼),视力均有不同程度的提高。结论三联手术是治疗儿童角膜合并白内障疾病的一种有效的方法。     

角膜穿孔伤伴外伤性白内障手术时机方法探讨

目的探讨角膜穿孔伤合并外伤性白内障的手术时机及手术方法。方法对23例（23眼）角膜穿孔伤合并外伤性白内障中的20例立即进行角膜全层裂伤清创缝合术。全部23例于伤后2—7天施行晶状体超声乳化吸出及折叠式人工晶状体植入术。其中囊袋内或睫状沟植入折叠式人工晶状体14例，单襻缝合固定折叠式人工晶状体9例。结果术后矫正视力低于0．05者2眼，0．05-0O．25者6眼，0．3-0．8者15眼。未见严重并发症。结论角膜穿孔伤合并外伤性白内障急诊行清创缝合术，并于2—7天内行晶状体超声乳化吸出及折叠式人工晶状体植入术，可以减少术中术后并发症。     

儿童角膜穿孔伤伴外伤性白内障手术治疗21例

目的观察儿童角膜穿孔伤伴外伤性白内障的，临床处理。方法回顾性分析21例（21眼）儿童角膜穿孔伤伴外伤性白内障的治疗经过，总结其手术时机、方法、并发症及并发症的防治。术后随访8~36个月。结果16眼术后视力提高，其中9眼提高大于5行；常见的远期并发症是后囊视轴区混浊（15眼）、虹膜后粘连（11眼）。结论对儿童角膜穿孔伤伴外伤性白内障者，应掌握其手术时机及方法，认识增生反应与并发症的关系并积极预防并发症。     

后囊破裂的外伤性白内障手术治疗

目的 探讨角膜穿孔伤伴后囊破裂的外伤性白内障手术时机、手术处理技巧和人工晶状体植入方法与原则.方法 角膜穿孔伤伴后囊破裂的外伤性白内障53例（53眼）,伤后4～11天,根据囊破裂、玻璃体视网膜等后段紊乱程度选择单纯超声乳化、晶状体皮质吸取,品状体切除联合玻璃体切除术处理后段紊乩,其中39眼（73.59%）一期植入人工晶状体,12眼（22.64%）二期植入人工晶状体.结果 术后6月矫正视力：低于0.1者3眼（5.66%）,0.1～0.25者13眼（24.53%）,0.3～0.6者28眼（52.83%）,大于0.6者9眼（16.98%）.人工晶状体偏位3眼,人工晶状体夹持2眼,人工晶状体脱位1眼.结论 角膜穿孔伤伴后囊破裂的外伤性白内障伤后应及早手术,并根据其眼前段紊乱的程度及是否伴有眼后段组织严重损害,选择适当的手术方式并适时植入人工晶状体.     

角膜穿孔伤并外伤性白内障手术治疗临床观察

目的探讨角膜穿孔伤合并外伤性白内障手术治疗的效果。方法对16例(16眼)角膜穿孔伤合并外伤性白内障手术治疗，全部行角膜全层裂伤修补术。择期行现代白内障囊外摘出、人工晶状体植入术。其中，后房型人工晶状体14眼、后房缝合型人工晶状体2眼。结果术后视力：低于0．05者3眼；0.05-0．25者4眼、0.3-0．5者9眼。并发症主要为后囊破裂玻璃体脱出，后发性白内障、虹膜炎症反应及角膜白斑等。结论角膜穿孔伤合并外伤性白内障，急诊行角膜全层修补术，间隔数天或数十天，择期行白内障囊外摘出人工晶状体植入。治疗效果良好，严格选择适应证和熟练掌握手术技巧及术后的合理治疗是手术成功的关键。     

角膜穿孔伤外伤性白内障人工晶状体二期植入

角膜穿孔伤合并外伤性白内障由于病情急、危害大、并发症多 ,而历来受到广大眼科医师的重视 ,对于白内障摘出及人工晶状体植入的时机问题素有争议。 1996年 2月以来 ,我们收治角膜穿孔伤合并外伤性白内障 7例。采用角膜穿孔伤修补术联合白内障一期截囊及人工晶状体二期植入的手术方式 ,获得良好效果。一般资料 :观察组 7例。男 5例 ,女 2例。年龄 17～ 36岁 ,均为单眼角膜穿孔伤 ,无眼内异物存留。伤口 3～ 7ｍｍ ,均伴有晶状体前囊不同程度的破裂 ,皮质部分浑浊。视力光感～ 0 12。手术方式 :术中前房内注入甲基纤维素 ,尽可能将虹膜回纳…     

角膜穿通伤并外伤性白内障的手术时机和术式的选择

探讨施行外伤性白内障摘出及人工晶体植入术的最佳手术时机和手术方式。方法 :5 4例角膜穿通伤合并外伤性白内障 ,急诊行角膜缝合术后 ,根据晶状体损伤的程度 ,选择不同的手术时机 ,将晶体皮质充分吸除干净 ,然后植入不同型号的人工晶体。结果 :手术均无严重并发症 ,视力大部分在 0 2～ 0 8之间 ,最佳达 1 2。结论 :选择最佳手术时机和合适型号的人工晶体 ,可使外伤性白内障人工晶体植入术达到较理想的效果。     

儿童外伤性白内障角膜缝合及人工晶状体植入

目的　评价儿童角膜穿孔伤修补 ,外伤性白内障摘出和后房型人工晶状体植入联合手术的疗效。方法　 1 6患者均给予降眼压处理 ,然后在全麻下行角膜缝合及白内障摘出人工晶状体植入手术。结果　脱盲率 1 0 0 % ,脱残率 81 .2 5 % ,矫正视力 >0 .5者占 62 .5%。结论　儿童外伤性白内障早期进行联合手术效果良好 ,可以防止弱视并促进双眼视功能的恢复     

人工晶状体植入治疗角膜穿孔外伤性白内障的临床研究

目的评价角膜穿孔伤合并外伤性白内障患者行，一期人工晶状体植入的疗效。方法对30例角膜穿孔合并外伤性白内障患者施行角膜清创缝合，一期人工晶状体植入，并对手术方法，时机、并发症，术后视力，双眼视觉进行研究。结果随访3～30月，平均8月。视力≥0．5者20眼，≤0．2者2眼。20例具有不同程度的双眼视觉。结论一期人工晶状体植入可使单眼角膜穿孔伤合并外伤性白内障患者获得良好的视力及双眼视觉。     

Homeostasis of the retinal micro-environment: I. Magnesium,potassium and calcium distributions in the avian eye

The concentrations of Mg²⁺, K⁺ and Ca²⁺ in the intraocular fluids (IOFs) and blood plasma of chickens and pigeons were determined by atomic absorption spectrophotometry. The Mg²⁺ concentration in the IOFs of both species was greatest in the liquid vitreous adjacent to the retina followed by aqueous > blood plasma > plasma dialysate. In contrast the concentration of K⁺ in the IOFs of both chickens and pigeons was greater in the aqueous than in the liquid vitreous. The concentrations of Ca²⁺ in all IOF compartments of chicken eyes were virtually identical and were lower than that of blood plasma. The concentrations of Mg²⁺ in the IOFs of the chicken, especially in the liquid vitreous, was remarkably stable; experimentally lowering or raising the plasma Mg²⁺ concentration over a relatively wide range had little or no effect on the Mg²⁺ concentration in the IOFs of these animals. We can conclude that a high Mg²⁺ and low K⁺ concentration in the extracellular fluids of the retina is maintained in the avian eye, as in the mammalian eye, by active transport processes across the blood-retinal barrier systems. Because the avian retina is completely avascular, the site of these homeostatic transport processes must be the epithelium of the retinal choroid and/or the pecten. These findings support the concept that the contribution of the vitreous to the homeostasis of the retinal micro-environment is inversely related in vertebrates to the degree of retinal vascularization.     

Vergleich der Durchmesserreaktion retinaler Arterien und Venen auf Flickerlicht

ZusammenfassungZiel In dieser Studie soll die durch Flickerlicht verursachte Durchmesserreaktion retinaler Arterien und Venen hinsichtlich Ausmaß und zeitlichem Ablauf verglichen werden.Methoden In die klinische Studie wurden 26 gesunde Probanden einbezogen. Der Durchmesser der retinalen Gefäße jeweils eines Auges wurde kontinuierlich mittels eines Retinal vessel analyzer gemessen. Jede Untersuchung bestand aus 100 s Baseline sowie 5 Perioden von 20 s Flickerlichtstimulation, gefolgt von 80 s Beobachtung.Ergebnisse Unmittelbar nach Flickerlicht dilatierten die Arterien um 6,9±2,8% (MW±STD) und die Venen um 6,5±2,8% (Unterschied nicht signifikant). Der Quotient aus arterieller und venöser Dilatation (AVDQ) betrug 1,25±0,69 (Spannweite 0,2 bis 2,8). Es konnte keine signifikante Altersabhängigkeit der arteriellen bzw. venösen Dilatation oder des AVDQ nachgewiesen werden. Die arterielle Dilatation ging nach 25,9±10,8 s in eine leichte Konstriktion von –2,7±1,4% über. Im Gegensatz dazu waren die Venen zum Zeitpunkt des individuellen Konstriktionsmaximums noch um 0,5±1,3% dilatiert (p<0,001).Schlussfolgerungen Die flickerlichtinduzierte Durchmesserreaktion retinaler Arterien und Venen unterscheidet sich bei Gesunden nicht in ihrem mittleren dilatativen Maximum, aber in Form und zeitlichem Verlauf des Abklingens der Dilatation.Unterstützung durch: BMBF 13N7999.Vortrag gehalten auf der 101. Jahrestagung der DOG, Berlin, September 2003.     

Acute Multifocal Placoid Pigment Epitheliopathy Associated with Cavernous Sinus Thrombosis

Acute multifocal placoid pigment epitheliopathy (AMPPE) has been associated with disease of the central nervous system. In this case report, we discuss a patient presenting with AMPPE in the setting of a new central nervous system association: cavernous sinus thrombosis.     

Dual nonlinearities regulate contrast sensitivity in pattern discrimination tasks

Many current psychophysical models propose that visual processing in cortex is hierarchical, with nonlinearities sandwiched between linear stages of processing. In earlier publications, we proposed a model of this type to account for masking effects found with spatial frequency and orientation discriminations. Our model includes two nonlinear mechanisms that regulate contrast sensitivity in early cortical mechanisms. The first is a local within-pathway nonlinearity that accelerates at low contrasts but is compressive at high. The second is a pooled nonlinear gain control process that operates over a broad range of neurons with different tuning characteristics. Here, we test predictions of the model for spatial frequency discriminations. The model predicts that at low contrasts, adding a grating mask oriented parallel to test gratings will improve discrimination performance via operation of the within-pathway nonlinearity, analogous to the "dipper effect" found with contrast discriminations. Adding an orthogonally oriented mask is predicted to have no effect at low contrasts, where pooled gain control processes contribute little to performance. At high contrasts, the model predicts that performance will asymptote and become independent of contrast with either parallel or orthogonal masks. The results confirm model predictions.