兔眼眶植入羟基磷灰石义眼台血管化的MRI评价

目的用MRI研究兔眼眶内植入羟基磷灰石（hydroxyapatite，HA）义眼台血管化过程，探讨义眼台血管化MRI表现和特点。方法12只新西兰白兔眼眶内植入直径12mmHA义眼台，于术后第2、3、4、5、6周对所有手术兔行双眼MR平扫及钆喷替酸葡甲胺（Gd-DTPA）增强扫描，计算义眼台强化区体积与义眼台体积比值（VE／VHA），对结果用单因素方差分析。并于第2、4周采用随机数字法抽取2只，第6周对剩余动物义眼台行组织病理学检查。结果术后第2、3、4、5、6周VE／VHA值分别为0．570±0．055；0．787±0．036；0．995±0．014；1．000±0．000；1．000±0．000。第2、3、4周VE／VHA值逐渐增加，均数间比较差异有统计学意义（F=233．094，P=0），第4、5、6周均数间比较差异无统计学意义（F=0．686，P=0．520）。术后2周病理显示义眼台周边有纤维血管生长，第4、6周整个义眼台完全血管化。结论MRI可直观、准确地评价义眼台血管化的程度和范围。     

脉络膜挫伤

回顾６４例外伤性脉络膜挫伤。多发于２０－３０岁的青年男性；最常见有拳击伤；临床主要表现为视力下降，眼底可见脉络膜出血灶及裂伤口，荧光眼底血和造影可帮助诊断。脉络膜挫伤多发生于黄斑部，其次为视乳头周围，多为单个，１－ＰＤ大小，脉络膜破裂的形态多为长弧形，脉络膜出血多为圆形；脉络膜破裂与出血常同时出现。     

人子宫内膜植入兔眼前房模型的研究

本实验成功地将人子宫内膜植入到１５只去卵巢新西兰雌兔的眼前房，并给每只兔外源补充雌二醇（Ｅ２）１００μｇ／ｄ和孕酮（Ｐ）８ｍｇ／ｄ。在内膜植入期间每只兔皮下注射总量为９ｍｇ的霉酚酸（ｍｙ－ｃｏｐｈｅｎｏｌｉｃａｃｉｄ）以防免疫排斥反应。在眼前房的人子宫内膜存活了２８．４４±８．６５天，兔血清Ｅ２和Ｐ的平均值分别为１６１．７１±１５．１３和３８．８８±７．４５ｐｍｏｌ／Ｌ。前房液中Ｅ２和Ｐ浓度在植入人子宫内膜前后分别为２４．８０±１６．５３和１７０９．２５±４７５．１０ｐｍｏｌ／Ｌ，２．００±０．５３和１２．２２±３．８１ｎｍｏｌ／Ｌ。树脂切片验证人子宫内膜植入兔眼前房第５天就能与虹膜附贴并有血管发生。来自巩膜的血管分布在子宫内膜周围。扫描电镜观察人子宫内膜分化成分泌细胞和纤毛细胞。植入人子宫内膜后，前房液的蛋白浓度高于植入前。可以证明该模型可用来研究人子宫内膜对药物的反应和通过对前房液的测量研究子宫内膜的分泌功能。     

GABAergic and glycinergic inputs to the rabbit oculomotor nucleus with special emphasis on the medial rectus subdivision

Contradictory results have been reported about the inhibitory input to the medial rectus subdivision of the oculomotor nucleus of the cat. In the present ultrastructural study, we quantified the GABAergic and glycinergic terminals in the various subdivisions of the rabbit oculomotor nucleus with the use of post-embedding immunocytochemistry combined with retrograde tracing of horseradish peroxidase. The density of the GABAergic input to the medial rectus subdivision was as substantial as that to the other subdivisions and the postsynaptic distribution of the GABAergic and glycinergic innervation did not differ among the different oculomotor subdivisions.     

眶骨延长术治疗眼球突出的实验研究

目的探讨眶骨延长术扩大眶容积治疗眼球突出的可行性。方法1年龄山羊6只,环行截开右侧眶壁,于眶上壁放置延长器,侧向延长1.5cm,经大体、X线、干骨标本及组织学观察成骨情况。结果6只山羊眶骨得到不同程度的侧向延长,延长侧随着眶骨容量的增加,眼球突度较自身对照侧为小。结论眶骨延长术可造成山羊眶骨侧向移位,有可能成为治疗眼球过度突出的方法之一。     

急性重度眼烧伤135例临床分析

目的了解急性重度眼烧伤的临床特点、预后及并发症发生情况。方法对笔者单位病案室保存的1977--2002年住院眼烧伤患者135例（155只眼）的病历进行回顾性统计分析。分析不同深度、原因眼烧伤的眼表修复率、修复时间、致盲情况及并发症。结果治疗后Ⅲ度眼烧伤的修复时间短于Ⅳ度眼烧伤，其修复率也明显高于Ⅳ度眼烧伤（P〈0．01）；在不能修复的Ⅳ度眼烧伤中，酸烧伤致角膜穿孔6只眼，显著高于碱烧伤（1只眼，P〈0．05）。Ⅲ度眼烧伤视力≥0．05者有38只眼，〈0．05者51只眼；Ⅳ度眼烧伤视力≥0．05者0只眼，〈0．05着66只眼。78只酸、碱烧伤眼中，52只眼致盲，致盲率为66．7％；77只热烧伤眼中，65只眼致盲，致盲率为84．4％。Ⅲ度眼烧伤的并发症发生率低于Ⅳ度眼烧伤。其中Ⅲ度眼烧伤角膜穿孔、睑球粘连的发生率（1．1％、36．O％）均显著低于Ⅳ度眼烧伤（27．3％、59．1％，P〈0．01）。在酸烧伤患者中，角膜穿孔及睑外翻的发生率（29．2％、37．5％）较高。而热烧伤患者中眼睑球粘连的发生率（53．2％）较高。结论Ⅳ度眼烧伤伤后的预后差，致盲率高。目前的治疗方法尚不能完全改善其视功能及预后，有待进一步研究。     

Analysis of saccadic short-term plasticity in three dimensions

The capacity for short-term adaptation is a well-established property of the horizontal (H) and vertical (V) components of saccades. It allows these directional components, which clearly serve the goal of foveation, to maintain their precision even under changing circumstances. Torsional (T) saccade components, on the other hand, which deal with the orientation of the target on the fovea, have hardly been investigated in adaptation experiments. They appear to be severely restricted by Listing's law during fixations and saccades. The main purpose of Listing's law is far from obvious but could be visual or oculomotor. Better knowledge of the adaptive capacity of the saccadic system in the torsional direction could throw new light on the functional significance of this interesting neural strategy. To study short-term plasticity in the torsional components of saccades, binocular 3D-eye positions were measured, using magnetic search foils. Five normal human subjects were instructed to make uni-directional refixation saccades, while they viewed a large visual scene. To induce a change in the torsional component, the complete stimulus was rapidly rotated during these saccades. We thoroughly investigated the torsional responses of the saccadic system, to see if any short-term adaptive response in torsional direction was induced, in which case the notion of a visual purpose for Listing's law would be strengthened. In none of our experiments, however, did we find any clear adaptive response in torsional direction. To further investigate the reliability of this result and to ascertain that our experimental conditions allowed classical gain adaptation, we also did experiments designed to achieve a combination of torsional adaptation and classic gain shortening in one of the directional components. While gain adaptation was very obvious, none of the experiments provided evidence for a short-term effect in torsion. We conclude that our experiments do not support a purely visual basis for Listing's law.     

Retinal specificity in eye fragments: investigations on the retinotectal projections of different quarter-eyes in Xenopus laevis

According to Sperry's chemoaffinity hypothesis, the projection of a small eye fragment with a reduced amount of optic fibres should be restricted to that position in the optic tectum corresponding to its own specificity. However, previous investigations on different types of quarter-eyes in Xenopus laevis have revealed that their retinal projection was always restricted to the rostral part of the tectum, no matter what the origin of the remaining retinal quadrant. To get an indication of the state of specificity in such eye fragments, we investigated by electrophysiological and histological methods several features of the retinal projections of temporoventral (TV), naso-ventral (NV) and ventral (V) quarter-eyes which referred to their positional identity. Irrespective of their different origins, the projections were always located in the rostral part of the tectum, the size of the innervated tectal area depending for all fragment types on the size of the quarter-eyes, i.e. number of optic fibres. However, quantitative analyses revealed that with increasing eye size the various fragments expand their projections preferentially into those tectal areas that match their original specificity: TV projection is more concentrated in the rostral tectum, NV eyes expand their projections mainly to the caudal tectum, and V eyes enlarge their projections equally into the medial and caudal tectum. In addition, fibre-tracing experiments with cobaltic lysine showed that, according to the different origins of the quarter-eyes, retinal fibres follow the appropriate branch of the optic tract selectively: fibres of NV and V eyes pass mainly through the medial tract, and most fibres of TV eyes innervate the rostral tectum directly from a central position between the two side branches. All these findings suggest that the different types of quarter-eyes retain their original positional identity. Thus, their rostrally located retinotectal projections are not in register with their retinal specificity. We conclude that in X. laevis local positional markers in the tectum, if present at all, do not influence the development of the retinotectal projection. Instead we suggest a concept of self-sorting of the optic fibres, which can account for the partial innervation of the rostral tectum in different types of quarter-eyes.     

Human cyclovergence as a function of stimulus frequency and amplitude

Summary By the use of scleral search coils a continuous record of human cyclovergence was obtained while two identical 80° textured patterns, presented dichoptically, oscillated in the frontal plane in counterphase through 1, 3 and 6° of cyclorotation at frequencies between 0.05 and 2 Hz. The amplitude and gain of the response decreased exponentially with increasing stimulus frequency. As stimulus amplitude increased, response amplitude also increased but gain was highest for low-amplitude cyclorotations. For an amplitude of 1° and a frequency of 0.05 Hz the gain reached 0.87 for two subjects. The phase lag increased from a few degrees at a frequency of 0.05 Hz to over 100° at a frequency of 2 Hz. These results suggest that cyclovergence is designed to correct for small, slow drifts in the stereoscopic alignment of the images in the two eyes. Although the disparity in the textured display was not interpreted as slant, it provided a strong stimulus for cyclovergence. The cyclovergence caused a transfer of cyclodisparity into a superimposed vertical line, which was then perceived as slanting in depth.     

正常人眼球直肌Pulley功能位置的动态磁共振成像研究

目的研究正常人眼球运动动态磁共振成像（MRI）4条直肌Pulley（滑车）的功能性位置。方法采用西门子公司Sonata1.5T超导型MRI扫描仪,应用眼球运动动态MRI技术,获取20名正常人（20个眼眶）眼球原在位及上转、下转、内转、外转20度时垂直于眶轴的眼眶冠状位MRI图像。以眼球中心为原点建立三维坐标系,应用ScionImage医学图像测量软件分别测量各层面眼球垂直转动时水平直肌、眼球水平转动时垂直直肌的横截面质心。根据各层面直肌横截面质心的坐标值建立直线回归方程,分别求得眼球垂直转动时内、外直肌径路及眼球水平转动时上、下直肌径路直线回归曲线斜率变化最大的一点,即为该直肌Pulley的功能性位置。对4条直肌Pulley相对于眼球中心的坐标值（X、Y）进行统计。结果内直肌Pulley位于眼球中心后4mm,内14.7mm,下0.3mm;外直肌Pulley位于眼球中心后8mm,外9.8mm,下0.3mm;上直肌Pulley位于眼球中心后6mm,内1.6mm,上11.5mm;下直肌Pulley位于眼球中心后6mm,内4.4mm,下12.7mm。结论应用眼球运动动态MRI技术,分析眼球转动时直肌径路的变化,可证实4条直肌Pulley的存在并确定其功能位置。