孔源性视网膜脱离年龄相关因素分析

目的 探讨孔源性视网膜脱离不同年龄段的发病相关因素、网脱特点、手术效果比较.方法 对2007年8月到2008年8月收治孔源性视网膜脱离117例,按年龄划分为:≤18岁青少年组29例(34只眼);19～64岁中年组53例(56只眼);≥65岁老年组35例(35只眼).对三组的临床特点、治疗效果进行对比及分析.结果 青少年组引起孔源性网脱相关因素中,高度近视、外伤因素的发病率较老年组均显著增高;青少年组引起孔源性视网膜脱离相关因素高度近视的发病率与中年组比较,差别无显著意义;青少年组引起孔源性视网膜脱离相关因素中外伤的发病率较中年组显著增高.青少年组及中年组孔源性视网膜脱离裂孔其中巨大裂孔、锯齿缘截离发病率较老年组显著增高,老年组中黄斑孔发病率较青年组及中年组显著增高,视网膜脱离范围累及黄斑区的青少年组、中年组及老年组相比较,青少年组低,差别有显著意义.青少年组、中年组、老年组术后视网膜复位率无显著差别.结论 青少年、中年及老年孔源性视网膜脱离比较,临床特点不同,但治疗效果无显著差异.     

The role of presaccadic compression of visual space in spatial remapping across saccadic eye movements

When multiple bars are briefly flashed near the saccadic goal on a visual reference just before a saccade, the total width of the multiple bars appears to be compressed toward the saccadic goal. We show that presaccadic compression of visual space is related to the attribution of the displacement of a visual stimulus to the displacement of another stimulus appearing after the saccade. Subjects observed a bar and a ruler. The bar was displaced during a saccade and the ruler disappeared briefly at the same time, and then the ruler reappeared at the same location after the saccade. The subjects had the impression that the bar appeared to remain stationary and the ruler appeared to be displaced after the saccade. This impression occurs strongly when the amount of the compression of visual space reaches the maximum at the saccade onset. Also, it occurs only at the saccadic goal in the same way as presaccadic compression of visual space. Saccadic suppression of displacement was equivalent at the saccadic goal and in the location opposite to the saccadic goal, indicating that the attribution of the bar displacement to the displacement of the ruler appearing after the saccade is not a consequence of saccadic suppression of displacement. Furthermore, performing a direction discrimination task showed that the bar appears stationary at the saccadic goal during compression of visual space even when the bar was actually displaced. We interpret these results as showing that presaccadic compression of visual space establishes the location of the saccadic goal (the bar) as a reference and then the location of the ruler is remapped relative to the reference location after the saccade, resulting in the illusory displacement of the ruler.     

A physiological study of acoustic blinking reflex in the cat

Blinking reflex was elicited by acoustic stimulus to investigate the reflex pathway in the encéphalo isolé cat. Reflex responses were recorded using electromyography (EMG) of the orbicularis oculi. The investigation was as follows: After stimulation by a loud click sound, the EMGs of the orbicularis oculi were elicited bilaterally. Latencies were 17-20 msec on the ipsilateral side, and 19-21 msec on the contralateral side. By electrical stimulation of the peripheral nerve in the cochlea and the acoustic nerve EMGs were also obtained. The latencies of the electrical stimulation responses correlated well with the latencies in the EMGs obtained through sound stimulation. The evoked potentials after auditory and electrical stimulation were obtained in several nuclei in the brainstem. The conduction time between two nuclei was calculated by measuring the latency of discharges in each nucleus. The alteration of the evoked discharge was observed through surgical transection of the brainstem. After each successive surgery the EMG showed differences in responses. Thus, the location of the neural connections of the pathways were differentiated in the brainstem. From this, we concluded that the reflex arc has the following pathway: The acoustic input to the ventral cochlear nucleus (VCN) is relayed to the acoustic route of the superior olivary complex and to the lateral lemniscus. Then, the impulse reaches the VIIth nucleus via the pontine reticular formation in the ipsilateral side. On the other hand, the input to the VCN crosses over the trapezoid body to the superior olivary complex. Then, the impulse uses the same pathway as described for the contralateral side. Finally, the pathway of the acoustic blinking reflex is located more caudally than that of the tactual blinking reflex. The comparison of the recordings of both reflexes is useful clinically, as a diagnostic method to study the function of the brainstem.     

A case report on the change of the refractive power after a blunt trauma

PURPOSE: To determine the pathogenesis of transient myopia after blunt eye trauma. METHODS: In one patient, the refraction of both eyes (the left eye was injured, but the right eye was not) was measured with an autorefractometer. The cycloplegic refraction was measured at the early stage of trauma and again 3 months after the blunt eye injury. The angle and depth of the anterior chamber, the ciliary body, and the choroids were examined by ultrasound biomicroscopy (UBM) over 3 months. The depth of the anterior chamber, the thickness of the lens, and the axial length were measured by A-scan ultrasonography in both eyes. During the 3 months after the injury, we made comparisons between the menifest and the cycloplegic refractions, the depths of anterior chambers, the thickness of the lenses, the axial lengths, and the UBM-determined appearances of the angles and depths of the anterior chambers, the ciliary bodies, and the choroids in both eyes. RESULTS: We suspect that the depth reduction in the anterior chamber, the increase in anterior to posterior lens diameter, and the edema in the ciliary body are all related to the change in the refractive power following the blunt trauma. CONCLUSIONS: Ultrasound biomicroscopy (UBM) and ultrasonography of the anterior segment in the eye may be helpful to diagnose and confirm changes in the refractive power that occur after trauma.     

Observations on the intraocular changes associated with accommodation: an experimental study using radiographic technique

To visualize the intraocular changes during accommodation, especially in the ciliary body and vitreous, a new radiographic technique was introduced. Radiopaque material, both water-soluble and oily mixture, was injected into the vitreous of the living cat through the sclera beneath the insertion of the superior rectus muscle. An X-ray beam was directed perpendicularly to the axis of the eye, so that the radiographs obtained offered a lateral view of the intraocular structures. The ciliary or superior cervical ganglion was stimulated electrically.During stimulation of the ciliary ganglion, besides the changes in the lens and iris, some movement was observed in the vitreous; this is thought to cause pressure upon the lens at the equator toward the front. The posterior portion of the valley between the ciliary processes also became swollen toward the inner direction of the eyeball. This could account for the relaxation of the zonule attached to the anterior surface of the lens, demonstrating a new function of the cat ciliary body, namely a sphincter-like action.On sympathetic stimulation no change was observed in the lens, the valley between the ciliary processes and the vitreous.     

Clinical characteristics of anomalous correspondence

The correspondence status of 68 constant, early-age onset strabismics was evaluated with three common clinical tests to determine the prevalence of anomalous retinal correspondence (ARC) and which clinical features of the strabismus were most highly associated with the ARC. Ninety-six per cent, 71%, and 51% of the patients manifested ARC with the striated lens test, the synoptophore, and the afterimage test, respectively. The clinical features of the strabismus that were correlated, although weakly, with the diagnosis of ARC were: (1) the magnitude of the deviation at near for the striated lens test; (2) the age of the patient at the time of testing and the laterality of the deviation on the synoptophore; and (3) the age of the patient at the time of testing, the change in the deviation from distance to near, and the spherical equivalent refractive error for the afterimage test. A low correlation also existed between the age of the patient and the depth of ARC (superficial or deep-rooted). We conclude that the clinical features of strabismus cannot be utilized effectively to predict the status of retinal correspondence.     

Organization of ascending projections from the optic tectum and mesencephalic pretectal gray in Rana pipiens.

The ascending projections from the dorsal mesencephalon to the thalamus and pretectum in Rana pipiens were investigated by using the anterograde and retrograde transport of HRP with regard to two major issues: (1) the degree of tectotopic organization in the projections, and (2) their cells of origin. The results indicate that the spatial organization of the tecto-thalamic tract is specifically related to the laminar organization of the contributing tectal efferent neurons. Axons of neurons in the superficial portion of tectal layer 8 exit the tectum through layer 9 and travel in the superficial portion of the dorsal and ventral tecto-thalamic tracts and innervate the nucleus lentiformis mesencephali, the posterior lateral dorsal nucleus, and corpus geniculatum. The distribution of terminals within these structures varied with the tectal HRP-injection site. HRP injections in the ventral tecto-thalamic tract retrogradely labeled neurons in the superficial portion of tectal layer 8 across the lateral and caudal portion of the tectal lobe. HRP injections into the dorsal tecto-thalamic tract, at the level of the pretectum, retrogradely labeled pyriform neurons in the superficial portion of tectal layer 8 in the rostral and medial portions of the tectal lobe. With regard to the deep tectal layers, axons from pyramidal neurons in layer 6 and ganglionic neurons in layer 8 leave the tectum through layer 7, travel in both the dorsal and ventral tecto-thalamic tracts, and are located internal to the axons of the pyriform neurons of superficial tectal layer 8. The majority of the ganglionic neurons project to the posterior lateral ventral nucleus and the anterior lateral nucleus. The distribution of terminals within these nuclei did not display a tectotopic organization. A second major projection to the thalamus originates from the mesencephalic pretectal gray and innervates the nucleus lentiformis mesencephali, the posterior lateral dorsal nucleus, the anterior lateral nucleus, dorsal and ventral divisions of the ventral lateral thalamus, and the nucleus of Bellonci. Other axons from the mesencephalic pretectal gray terminate in the contralateral, medial portions of the posterior lateral dorsal thalamus, the ventral lateral thalamus, and the anterior lateral nucleus. The isthmo-tectal projection was also retrogradely labeled following tectal injections of HRP. This pathway travels in the most ventral portion of the ventral tecto-thalamic tract; its axons passed over the lateral margin of the endopeduncular nucleus bilaterally, and crossed the midline in the caudal portion of the optic chiasm. Extensive, bead-like varicosities were observed on these axons both in the endopeduncular nucleus and in the posterior optic chiasm.(ABSTRACT TRUNCATED AT 400 WORDS)     

Visual sensitivity to temporal change in focus and its relevance to the accommodation response

Measurements were made of the ability of observers, whose accommodation had been paralysed, to detect the small changes in contrast resulting from sinusoidal, oscillatory changes in the dioptric focus of test objects, as a function of the mean position of focus. Variables studied included the form and wavelength composition of the test object, the diameter of the entrance pupil of the eye and the temporal frequency of the focus change. The dioptric amplitudes of the thresholds found (approximately 0.1 D) were comparable with the normally observed amplitudes of the microfluctuations of the accommodation system of the eye. A maximum for the threshold change of focus was found to occur about a mean position of focus corresponding to the nominal "best-focus". Two threshold minima occurred symmetrically on either side of this position of optimal mean focus; the positions of these minima depended on the spatial frequency content of the test object and the pupil diameter. The results are interpreted in terms of the corresponding through-focus changes in optical modulation transfer of the eye and data on the sensitivity of the visual system to spatial and temporal modulation. For sinusoidal grating test objects, it appears that the results can qualitatively be explained if it is assumed that the detectable focus change is such that the ratio of the modulation change in the retinal image, produced by the focus change, to the modulation at the mean position of focus is constant. Results for targets of broad spatial bandwidth suggest that sensitivity to focus change may be dominated by spatial frequency components approximately 5 c/deg. The implications of the data for the understanding of the accommodation control system are briefly considered.     

The posterior portion of the eyeball and the muscle cone in cases of high myopia

PURPOSE: To study the displacement of the eyeball of high myopia in the muscle cone. METHODS: Three patients with esotropia with high myopia(myopic esotropia group), seven patients with high myopia without esotropia (high myopia group), and eight controls(control group) were examined. Using magnetic resonance imaging, the outer axial length and the displacement of the posterior portion of the eyeball in the muscle cone were measured. In order to neglect individual differences, the coronal scanning was perpendicular to the orbital axis. The displacement was measured in the plane 2 mm and 4 mm anterior from the globeoptic nerve junction. The distance of the displacement was represented by the distance from the center of the globe to the center of the muscle cone. RESULTS: The displacement in the plane 4 mm anterior (mean +/- standard deviation) was greater in the order of the myopic esotropia group(1.6 +/- 0.64 mm), the high myopia group(1.2 +/- 0.51 mm), and the control group(0.059 +/- 0.35 mm). The displacement of the eyeball was largest in the myopic esotropia group(p < 0.001). The outer axial length and the distance of the displacement in all cases was correlated significantly(r = 0.93, p < 0.01). Moreover, the eyeballs of the myopic esotropia group and the high myopia group were displaced upwards in the temporal area. CONCLUSIONS: The posterior portion of high myopia was displaced upwards in the temporal area in the muscle cone regardless of the presence or absence of esotropia. The eyeball originally elongates upwards in the temporal area, not towards the weakest part of the muscle cone.     

Threshold changes near the light-dark border: A comparison of real and equivalent background lights

Increment thresholds were measured at several positions within a rectangular illuminance-step background, both during and after the background's presentation. In the region of the step, Mach bands were observed. On the bright side of the border, the increment thresholds were elevated relative to those measured in the center of the higher-illuminance field. However, the thresholds measured in the dark, after preadaptation to the step background, were similar both in the center of the field and near the border. In the dark region, on the other hand, the increment thresholds were elevated (contrary to expectation) and so were the absolute thresholds measured after preadaptation to the step background. It is concluded that inhibitory interactions do not occur in the presence of dark light and that the threshold elevation on the dark side of the border is caused by scattered light.     

Arterial vascularization of the levator muscle of the upper eyelid

The arterial vascularization of the levator to the anterior half of the nasal edge and the posterior half of the inferior face come from the supra orbital artery or from a branch of the ophthalmic artery. The posterior third receives its arterial supply from the posterior ethmo?dal artery. The anterior portion and the lateral and medial horns get their blood supply from the lacrimal artery but the presumed supply from the palpebrae arteries has not been shown in this study. The radio-anatomic study of the muscle defines three of different arterial supplies: the lacrimal artery in the anterior part; the supra orbital or ophthalmic artery in the middle and the posterior ethmo?dal artery, posteriorly. Some arterioles traverse the entire muscle from single pedicle (supra orbital) but in a third of cases the lateral arteriole arises from the posterior ethmo?dal artery. They anastomose in the anterior portion of the muscle with the arterioles arising from the lacrimal artery through the lacrimal gland. The radio-anatomic pictures emphasize the great supply from that origin. The major practical implication of this study is the importance of better hemostasis in anterior levator surgery particularly during ptosis surgery.     

Crossing axons in the third nerve nucleus.

The research presented in this paper studied the pathway taken by the crossed fibers of the third nerve nucleus in an animal whose nucleus has been well mapped and found to correlate well with higher mammals and man. Autoradiography using tritiated amino acid labeled the cell bodies an axons of the left side of the oculomotor nucleus of the cat. Axons so labeled could be seen emerging from the ventral portion of the left nucleus through the median longitudinal fasciculus (mlf) to join the left oculomotor nerve. Labeled axons were also seen to emerge from the medial border of the caudal left nucleus, cross the midline, and pass through the right nucleus and the right mlf to join the right oculomotor nerve. These latter axons must be the crossed axons of the superior rectus and levator palpebrae subnuclei. Since the path of these crossed axons is through the caudal portion of the nucleus of the opposite side, the destruction of one lateral half of the oculomotor nucleus would result in a bilateral palsy of the crossed subnuclei. Bilateral palsy of the superior rectus and bilateral assymetrical palsy of the levator palpebrae muscles would result.     

贝母素甲对体外培养甲状腺相关眼病患者眼眶成纤维细胞增殖的影响

目的:观察贝母素甲(PM)对体外培养甲状腺相关眼病患者眼眶成纤维细胞(orbital fibroblast,OF)增殖的影响。方法:采用体外培养的正常人和甲状腺相关眼病患者的OF,将PM和阳性对照药物地塞米松(Dex)分成不同浓度组,以MTT法检测其对细胞增殖的影响。结果:对体外培养甲状腺相关眼病患者OF的增殖,PM具有与Dex相似的抑制作用,二者均有明显的剂量依赖性。但PM对甲状腺相关眼病患者OF增殖的抑制作用明显优于正常人(P<0.05),而Dex则无此选择性。结论:浙贝抑制了甲状腺相关眼病患者OF的增殖。     

Binocular interactions in visual evoked cortical potentials with two light-emitting-diodes

Binocular interaction for a central field was studied with transient scalp visual evoked cortical potentials (VECPs) using two light-emitting-diodes. VECPs were obtained for binocular and monocular visions with dominant and non-dominant eyes, and arithmetical sums of monocular VECPs with dominant and non-dominant eyes were calculated. Amplitude and latency of remarkable initial three peaks were tested with the multivariate analysis of variance. Significant differences were noted among the four VECPs. Pairwise comparisons showed that (1) the amplitude of the first peak for the binocular VECPs was larger than that for the monocular VECPs but smaller than that for the sum-VECPs; the latency of the first peaks for the binocular VECPs were earlier than that for the monocular VECPs with the non-dominant eye; (2) the amplitude of the first negative peak for the sum-VECPs was larger than that for the binocular VECPs, and the peak latency for the sum-VECPs showed later than that for the binocular VECPs; (3) the amplitude of the second positive peak for the binocular VECPs and monocular VECPs with the dominant eye was larger than that with the non-dominant eye, but smaller for the binocular VECPS than that for the sum-VECPs; the latency for the binocular VECPs showed earlier than that for the monocular VECPs with the dominant eye and for the sum-VECPs. Binocular suppression was noted in amplitude for the three peaks and binocular facilitation was noted in latency for the latter two peaks. This revised version was published online in July 2006 with corrections to the Cover Date.     

Age-related changes in carbonic anhydrase of toad lens

Carbonic anhydrase in the toad lens is immunologically identical to the (high activity) enzyme form present in the erythrocyte. As with the erythrocyte carbonic anhydrase, electrofocusing of the freshly-extracted lens enzyme separated three variants with isoelectric points of 6.1, 5.7 and 5.4, all of which exhibited inhibition properties characteristic of the high activity type of carbonic anhydrase. No evidence of the low activity form of the enzyme was found. In contrast to the erythrocyte isoelectric variants, which are stable in vitro, the three variants of lens carbonic anhydrase exhibited progressive anodization in the course of purification and during storage, and could not be isolated in the original form. Acidification of lens carbonic anhydrase appears to be part of the in vivo aging process of the enzyme protein: the still-active enzyme from the oldest lens region--the nucleus--exhibited a considerably lower isoelectric point than the enzyme extracted from the younger, soft fibers of the lens. Although the specific activity of the carbonic anhydrase from the fibers of lens nucleus was considerably lower than the activity of the enzyme from the younger fibers, the observed modification (acidification) of the aged enzyme did not appear to affect substantially its binding properties towards acetazolamide nor the heat lability of the active protein.     

辅助切口与透明质酸钠在眼穿孔伤修复的应用

目的探讨在角巩膜穿孔伤修复手术中，采用角膜缘辅助切口加透明质酸钠的效果。方法138例（140眼）角巩膜穿孔伤修复手术中45例（45眼）伤口复杂及虹膜不易还纳者采用辅助切口加透明质酸钠的应用。结果45眼经此处理，人部分瞳孔圆形或接近圆形。4眼瞳孔撕裂散人，3眼虹膜部分缺损，所有患眼均未造成虹膜前粘连。结论此手术方法减少了虹膜恢复的困难及眼内组织损伤，增加了手术的安全性，减少了并发症。     

Power spectra of the natural input to the visual system

The efficient coding hypothesis posits that sensory systems are adapted to the regularities of their signal input so as to reduce redundancy in the resulting representations. It is therefore important to characterize the regularities of natural signals to gain insight into the processing of natural stimuli. While measurements of statistical regularity in vision have focused on photographic images of natural environments it has been much less investigated, how the specific imaging process embodied by the organism’s eye induces statistical dependencies on the natural input to the visual system. This has allowed using the convenient assumption that natural image data are homogeneous across the visual field. Here we give up on this assumption and show how the imaging process in a human model eye influences the local statistics of the natural input to the visual system across the entire visual field. Artificial scenes with three-dimensional edge elements were generated and the influence of the imaging projection onto the back of a spherical model eye were quantified. These distributions show a strong radial influence of the imaging process on the resulting edge statistics with increasing eccentricity from the model fovea. This influence is further quantified through computation of the second order intensity statistics as a function of eccentricity from the center of projection using samples from the dead leaves image model. Using data from a naturalistic virtual environment, which allows generation of correctly projected images onto the model eye across the entire field of view, we quantified the second order dependencies as function of the position in the visual field using a new generalized parameterization of the power spectra. Finally, we compared this analysis with a commonly used natural image database, the van Hateren database, and show good agreement within the small field of view available in these photographic images. We conclude by providing a detailed quantitative analysis of the second order statistical dependencies of the natural input to the visual system across the visual field and demonstrating the importance of considering the influence of the sensory system on the statistical regularities of the input to the visual system.     

3D-OCT对视交叉病变黄斑区视网膜神经节细胞复合体损害的诊断价值

目的观察蝶鞍区占位性病变对视交叉部的损害导致黄斑区视网膜神经节细胞复合体（mGCC）厚度的特征性改变及其诊断价值。方法回顾性系列病例研究。对11例确诊为蝶鞍部占位病变患者采用Topcon 2000型三维光学相干断层扫描仪（3D-OCT）测量mGCC厚度及视盘周围神经纤维厚度,分析mGCC损伤的图像特征和视盘周围神经纤维损伤特征。并对这11例患者采用OCTOPUS 101型自动视野计进行视野检查。将3D-OCT检查结果与相应的视野检查结果进行对照,评估两者的符合度。结果所选的11例蝶鞍区占位性病变患者中,2例因瘤体较小尚未侵犯视交叉部视路,视野和mGCC检查结果均未见异常;9例出现以中垂线划界的视野改变,其中7例为双颞侧偏盲,2例为同侧偏盲,肿物分别位于右侧视束起始部位和左侧视交叉后交界处。有视野损害的9例,3D-OCT检查均出现中垂线划界的mGCC环形的萎缩变薄或消失,与视野改变相对应。结论蝶鞍区占位性病变对视交叉部位的损害导致中线划界的双鼻侧mGCC变薄。与视野具有等同的定位作用。     

RPE transplants stabilize retinal vasculature and prevent neovascularization in the RCS rat.

Previous reports indicate that in the Royal College of Surgeons (RCS) rat a decline in the retinal vessel density accompanies the loss of the normal architecture of the deep bed. This begins at about three months with neovascularization that originates in the deep vessel bed and develops in the direction of the retinal pigment epithelial (RPE) cells by four months. A surgical technique has been developed recently for the transplantation of healthy RPE cells into the subretinal space of the RCS rat, resulting in the rescue of photoreceptor cells. This permits evaluation of the possibility that such transplants also protect the retinal vessels. We report for the first time: (1) the stabilization of the normal retinal vasculature by maintenance of the density and architecture of the deep vessel bed; and (2) prevention of neovascularization of the RPE by the surgical transplantation of healthy RPE cells into the subretinal space of the RCS rat. More specifically, we show a maintenance of the deep vessel bed density under the transplant in contrast to a significant reduction in the vessel density that had taken place in corresponding areas in nongrafted and sham injected controls at four months of age. The vessel density in the transplanted group is statistically different from the nongrafted and the sham injected groups. We also report a significant decline in the number of neovascularization profiles around the transplant site of the RPE-grafted RCS retina. We also note that the pathological changes in the vasculature of the RCS rat occur in a predictable central to peripheral gradient.     

Retinal detachment after perforating injuries of the eye. I. Analysis of anamnestic data related to the injury, analysis of deficiencies in the primary care of the eye injury and principles of prevention of post-traumatic retinal detachment

In 1977-1987 the authors operated by the cryosurgical method 69 patients on account of detachment of the retina. The detachment occurred in 37 patients after simple perforation of the eye and in 32 patients after perforation with a foreign intraocular body. In all patients the perforation penetrated as far as the vitreous body. In the first part of the paper the authors analyze in detail anamnestic data related to the injury: age, mechanism of injury, rapidity and method of surgical treatment, chemical nature of foreign body and its size, rapidity and method of extraction of the foreign body. In the subsequent part the authors define the principles of prevention of post-traumatic detachment of the retina during surgical treatment of the injury. Finally the basic shortcomings of primary treatment of the injury from the aspect of detachment of the retina are outlined, as recorded in the group treated by the authors.