糖尿病大鼠泪腺、结膜及角膜组织病理学观察

目的 探讨糖尿病造成的泪腺、角膜、结膜组织损伤。方法 雄性SD大鼠40只。随机分为糖尿病组和对照组，各20只。分别于成模后6、8、10、12周断颈处死大鼠，每组各5只。光镜下观察泪腺、角膜、结膜组织病理学改变。结果 糖尿病组随时间依次表现为泪腺细胞水肿、增生，腺泡及导管萎缩，纤维增生及淋巴细胞浸润，角膜上皮、基质层水肿，结膜杯状细胞减少。结论 糖尿病导致的泪腺、角膜、结膜等眼组织破坏是糖尿病性眼表病变的病理基础。     

BTX-B诱导大鼠干眼模型的建立及评价标准

目的：建立肉毒杆菌毒素B(BTX-B)诱导的大鼠干眼模型,为研究炎症参与的干眼症的发病机制和实验性治疗提供依据。

方法：健康雌性SD大鼠36只随机分为4组,实验组为三组,分别给予右侧泪腺注射0.1mL 1.25、5、10mU的BTX-B溶液,对照组右侧泪腺注射0.1mL生理盐水,分别在第3、7、14、28d行泪液实验Ⅰ(SⅠt)、角膜荧光素染色(FL)检查。另选取32只大鼠,随机分为两组,实验组大鼠右侧泪腺注射0.1mL 1.25mU的BTX-B溶液,分别于第3、7、14、21、42d时选取5只实验大鼠摘除泪腺组织,采用免疫荧光法和Western-blot 法对Lacritin蛋白进行定性和定量检测,组织病理学检测采用常规HE染色。

结果：模型制备中三个实验组均在第3d开始出现泪液分泌减少和角膜上皮损害,但两两之间差异无统计学意义(P>0.05),7d时达到高峰,14d时好转,28d时泪液分泌恢复正常,但角膜上皮仍见损伤。实验组和对照组大鼠泪腺组织中均仅见腺泡细胞表达Lacritin蛋白,实验组大鼠Lacritin蛋白含量明显下降,自第3d开始出现,7d时达到高峰,14d时好转,28d时开始恢复,42d时达到正常。

结论：泪腺注射1.25mU的BTX-B溶液可成功建立SD大鼠干眼模型,可见泪液分泌减少、角膜上皮损伤等干眼体征,可为干眼的发病机制和实验性治疗研究提供实验依据和基础; Lacritin蛋白仅在泪腺腺泡细胞中表达,其含量与泪液分泌量和干眼程度呈同步变化,可为干眼程度评价标准的完善提供新的依据。     

减少瞬目频率建立的蒸发过强型兔干眼模型

目的:通过减少瞬目频率建立蒸发过强型兔干眼模型。方法:新西兰大白兔12只随机分为实验组A,B和对照组C,每组4只。两实验组模拟荧屏终端(video display termi-nals,VDT)操作者的瞬目特点,用铁夹固定兔眼睑将其瞬目频率减少为实验前的1/3,8h/d。造模前和造模后3,7,10,14d行Schirmer试验、角膜荧光素染色和泪膜破裂时间(break-uptime,BUT)检查,造模前后自身对照。对照组置于相同环境下不进行干预。14d处死A,C组兔取结膜、角膜和泪腺组织行光学显微镜观察及杯状细胞计数对照;B组停止干预,于17,21,28d观察指标,28d处死取相同组织行光学显微镜观察及杯状细胞计数。结果:除A组7d和B组3d外,两实验组其余时间点Schirmer试验值与实验前相比都无明显改变(P>0.05)。从3d起,两实验组的角膜荧光素染色评分显著升高,BUT显著减少(P<0.05),随着时间推移变化程度逐渐加重。14dB组停止干预后上述差异仍存在。光镜下两实验组的角结膜上皮层以增生性改变为主,泪腺组织无明显变化。14dA组4个方位球结膜的杯状细胞数量都比对照组C组少,差异显著(P<0.01),以鼻侧和颞侧球结膜差别更明显。28dB组各方位球结膜杯状细胞数量仍明显低于对照组C组(P<0.01)。结论:减少瞬目频率能成功地建立蒸发过强型兔干眼模型。     

摘除泪腺和泪腺注射肉毒杆菌毒素A制备大鼠干眼模型的比较

目的：分别采用摘除泪腺法和泪腺注射肉毒杆菌毒素A法诱导大鼠干眼症模型,通过对比两种干眼症模型的临床表现、病理学特点和细胞因子变化,探讨其优缺点和适用范围。

方法：健康8周龄雄性Brown Norway大鼠30只,随机分为3组：A组左眼为空白组,B组摘除大鼠左侧主泪腺,C组左侧泪腺注射肉毒杆菌毒素A。比较实验前1d,实验后3、7、14、28、42d的泪液分泌量(SⅠt)、泪膜破裂时间(BUT)、角膜荧光素钠染色评分的变化。42d观察结膜、角膜和泪腺组织病理学改变; 通过实时荧光定量PCR对白细胞介素-6(IL-6)、肿瘤坏死因子α(TNF-α)和上皮生长因子(EGF)表达量进行检测。

结果：实验后第3d开始,B、C组均出现泪液分泌量持续性减少,与A组均有差异(P<0.05); 实验后第7d开始,B、C组均出现BUT持续性缩短以及角膜上皮染色明显增多,与A组比较有差异(P<0.05); 以上临床数据B、C组间比较均无差异(P>0.05)。A组角膜上皮细胞形态正常,B组及C组角膜上皮均存在不同程度表层细胞丝状分离,结膜杯状细胞数目明显减少,C组泪腺组织明显萎缩。B、C组结膜和角膜组织的EGF、TNF-α和IL-6表达量均显著增高,与A组比较均有差异(P<0.05)。B、C组间EGF和TNF-α的表达均无差异(P>0.05); 与C组比较,B组中IL-6的表达量更高(P<0.05)。

结论：摘除泪腺和泪腺注射肉毒杆菌毒素A均可以构建稳定的水液缺乏型大鼠干眼模型,建议根据实验设计及实验目的去选择合适的动物模型。     

皮下注射氢溴酸东莨菪碱建立兔干眼模型的实验研究

目的探讨兔皮下注射氢溴酸东莨菪碱建立于眼模型的有效性和眼表病理损害机制。设计实验研究研究对象健康新西兰大白兔9只。方法将9只白兔随机分为三组,每组3只。实验组皮下注射氢溴酸东莨菪碱,其中低剂量组（L,1．0mg／次）、高剂量组（H,2．0mg/次）,对照组注射等量生理盐水。注射时间点为每天8点、11点、14点和18点,连续30天。主要指标不同时间点用药前后泪液分泌量、泪膜破裂时间,角膜荧光素染色情况,结膜印迹联合PAS染色评价眼表上皮细胞表型。观察期末取角结膜、泪腺组织行HE染色光镜下观察。结果酚红棉线法测得高剂量（H）组注射前泪液分泌量为（16．25±2．299）mm,第21d时下降为（6．75±1．982）mm,对照组为（16．50±2．619）mm,差异具有统计学意义（P=0．000〈0．01）,同期低剂量组（L）为（15．00±2．390）mm,与对照组相比无明显差异。H组第3d出现BUT缩短,L组则第7d发生BUT的变化,此后BUT值均低于5s,对照组BUT大于20s。实验组均出现角膜荧光素染色阳性,H组出现时间早（3d）,持续时间长。L组和H组PAS染色与对照组相比,杯状细胞形态紊乱、核淡染,部分核固缩,L组和H组之间无明显差异。HE染色显示H组泪腺周围见散在淋巴细胞和腺腔凋亡性改变,角膜上皮呈重度瘤样增生基质层变性伴水肿,结膜杯状细胞反应性增多,固有层见淋巴细胞浸润数量增加。L组角膜浅层上皮轻度增生,细胞排列稍紊乱,结膜和泪腺组织病理改变轻微。结论兔皮下注射氢溴酸东莨菪碱,4次/d,2．0mg,次,可有效维持药物外周浓度,抑制泪腺分泌,引起角结膜上皮损伤,成功建立以泪液缺乏为主,炎症反应参与的干眼动物模型,为进行干眼发病机制研究和药物干预提供了理想的实验平台。     

局部滴用阿托品建立兔干眼模型的评价

目的评价滴用阿托品建立兔干眼模型的优劣。方法新西兰大白兔16只,随机选1眼滴用1%硫酸阿托品滴眼液,对侧眼作对照。用药前及用药后不同时间点对实验组及对照组行Schirmer试验、结膜角膜虎红染色、角膜荧光素染色、结膜印迹细胞检查。第35d取结膜、角膜及泪腺组织行光学显微镜检查,泪腺组织同时行电镜检查并采用酶标仪检测其中的乙酰胆碱浓度。结果滴用阿托品后第1d,实验组Schirmer试验值下降,荧光素染色及虎红染色积分上升(P<0·05),至用药后第1周表现最明显,之后逐渐减轻。用药前后杯状细胞密度未出现差异(P>0·05)。滴药后第35d,实验组结膜、角膜、泪腺组织光镜及电镜检查未见异常,泪腺中乙酰胆碱浓度[(18·99±9·79)μmol/mg]比对照组明显增高[(13·10±7·34)μmol/mg](P=0·0318)。结论滴用阿托品可以使兔很快出现干眼,但随时间延长而减轻,因而这种干眼模型不够理想。     

共刺激分子Tim-1在角膜移植排斥反应中的作用

背景 角膜移植是目前临床上治疗角膜盲可靠且有效的复明手段,角膜移植术后的免疫排斥反应是角膜移植失败的主要原因. 目的 研究共刺激分子Tim-1在大鼠角膜组织中的表达及其在角膜移植排斥反应发生和发展过程中的作用.方法 40只清洁级成年雌性Wistar大鼠随机分为正常对照组、自体角膜移植组和同种异体角膜移植组.正常对照组大鼠未行任何手术,自体角膜移植组分别以Wistar大鼠作为供体和受体施行穿透角膜移植术,而同种异体角膜移植组以SD大鼠角膜作为供体,Wistar大鼠作为受体行穿透角膜移植术,各组供体角膜植片均为3.5mm,植床直径为3.0 mm.分别于术后7d、14d在裂隙灯显微镜下观察术眼角膜炎症反应情况,按照Larkin的标准进行排斥反应评分,计算排斥反应指数（RI）,观察各组角膜植片的平均存活时间和植片存活率.术后7d、14d,3个组各取3只大鼠眼球制备角膜组织切片,分别行组织病理学检查和免疫组织化学检测,观察角膜组织的炎症反应和共刺激分子Tim-1蛋白在角膜组织中的表达;此外分别于术后7d、14d各组取5只大鼠角膜制备组织匀浆,采用实时荧光定量PCR法检测共刺激分子Tim-1 mRNA在大鼠角膜植片中表达量（吸光度,A）的变化.结果 术后7d,自体角膜移植组和同种异体角膜移植组大鼠角膜植片均出现轻度水肿;术后14 d,自体角膜移植组角膜植片水肿消失,植片透明,而同种异体角膜移植组大鼠角膜植片水肿增厚,呈灰白色混浊,可见新生血管形成.自体角膜移植组植片的存活率为100％,同种异体角膜移植组植片存活率为0,平均生存时间为（9.8±1.2）d.组织病理学检查表明,术后7d自体角膜移植组植片基质层可见炎性细胞浸润,但术后14d炎性细胞明显减少;同种异体角膜移植组术后7d植片水肿,基质层可见炎性细胞浸润,术后14 d阳性细胞大量增加,可见新生血管.免疫?     

应用滤过性手术在大鼠眼上建立结膜滤过泡瘢痕化模型的研究

目的探讨应用滤过性手术在大鼠眼上建立结膜滤过泡瘢痕化模型的可行性。方法选用35只健康成年SD大鼠作为实验动物,在全身麻醉下行单侧眼球滤过性手术,术后观察结膜滤过泡的形成情况,并观察眼前节反应;手术后1、3d,1、2、4周共5个时间点各处死3只大鼠,摘除其眼球,常规10％福马林固定,切片,HE染色,观察其病理改变,并以对侧眼作为正常对照。结果所有大鼠在手术后7d均有结膜滤过泡形成;手术后8d,结膜滤过泡消失,最长的结膜滤过泡能够维持21d。组织病理学观察显示,术后1d,结膜下组织疏松水肿,血管扩张、充血明显,有较多中性粒细胞浸润;术后3d,结膜下组织血管扩张、充血,除有中性粒细胞浸润外,还可见单核巨噬细胞浸润,结缔组织疏松、水肿较前减轻;术后7d,血管扩张充血程度较术后3d时减轻,有较多的纤维母细胞增生,纤维母细胞的细胞核呈椭圆形、胞质丰富,在纤维母细胞周围,可见少量疏松的胶原纤维形成;术后2周,纤维母细胞数量较术后1周时有所减少,细胞变细长,细胞核两端变尖,周围胶原纤维较术后1周时致密;术后4周时,结膜下组织血管多数闭合,细胞成分明显减少,纤维母细胞演变为纤维细胞,细胞核变细长,周围伴大量胶原纤维沉积,呈现瘢痕样改变。结论应用滤过性手术在大鼠眼上建立结膜滤过泡瘢痕化模型具有可行性,其病理改变是一个创伤修复的过程,该模型的建立不仅为青光眼手术后结膜滤过泡瘢痕化的防治,同时也为防治其他原因导致的结膜瘢痕化提供了新的研究方法。     

阈下能量经瞳孔热疗对正常大鼠视网膜的影响

目的 研究正常棕色挪威大鼠(BN大鼠)视网膜在810 nm激光阈下能量经瞳孔热疗(TTT)后的改变。方法 雄性BN大鼠36只，使用810 nm激光，采用不同阈下能量对BN大鼠进行TTT。分别于TTT后第1、3、7、14 d进行彩色眼底照相和眼底荧光造影(FFA)。TTT后6、12h，1、3、7、14d各处死6只大鼠，进行组织病理学观察。6、12h和1 d的组织用TdT介导dUTP缺口末端标记法(TUNEL)检查细胞凋亡。结果 TTT后第1 d可见大部分光斑处视网膜灰白色水肿。第3 d视网膜水肿减轻，RPE脱色素。其后视网膜逐渐出现色素沉着。FFA中可见到不同程度的高荧光。组织病理学切片上可见所有在眼底照相上曾出现灰白水肿的病灶，视网膜结构均有显著破坏。TUNEL染色可见视网膜全层均有细胞凋亡。TTT能量最低组6 h时凋亡细胞最多；激光斑旁视网膜较激光斑中央视网膜凋亡细胞多。结论 TTT阈下能量可引起不可逆的视网膜损伤，即使无病理改变也能引起视网膜细胞的凋亡。     

高原环境对兔泪液指标及相关解剖结构的影响

目的:探讨高原低压缺氧环境对兔泪液指标及相关解剖结构的影响。方法:选取18只健康新西兰兔,随机分为高原组和对照组,每组9只18眼。高原组饲养于西北特殊环境人工实验舱,模拟海拔6 000 m低压缺氧环境;对照组饲养于常压常氧的清洁动物房。分别于干预前、干预3、7 d, 2、4 wk采用RHCT-1角膜地形图仪干眼综合分析系统检测泪河高度、泪膜破裂时间,并采用泪液分泌试验测量泪液分泌量,同时利用拉曼光谱分析高原环境干预前后泪液成分的变化。干预4 wk采用苏木素-伊红(HE)染色观察下睑结膜、角膜、泪腺、哈氏腺的组织病理学变化,采用免疫组织化学法检测结膜组织中黏蛋白5AC(MUC5AC)的表达。结果:与对照组相比,高原组兔泪液分泌量、泪河高度、首次及平均泪膜破裂时间自干预3 d开始明显下降,且随观察时间的延长有显著差异(P<0.05);干预2 wk开始上述各指标增加。干预4 wk,高原组兔泪液成分中蛋白质、脂质含量较干预前增多,核酸含量较干预前减少,且与对照组相比,高原组兔角膜基质水肿增厚,结膜杯状细胞数量增多,MUC5AC表达水平升高,泪腺上皮细胞胞浆萎缩扁平,腺腔扩大,哈氏腺无明显...     

Segmentation and accuracy in copying and drawing: Experts and beginners

As part of an ongoing investigation into real-world copying and drawing, I recorded the eye-hand drawing strategies of 16 subjects with drawing experiences ranging from expert to novice while they copied a line drawing of a standing nude. The experts produced accurate copies whereas all the beginners produced marked inaccuracies of overall scaling, proportion and shape. Analysis of eye and hand movements showed that the experts alone segmented the original drawing into simple line sections that were copied one at a time using a direct eye-hand strategy not requiring intermediary encoding to visual memory. The results suggest that segmentation into simple lines defines the task-specific process of accurate copying, and that this process is restricted to experts, i.e. acquired through training and practice. Additional preliminary tests also suggest that a similar process may apply to drawing a model from life.     

Paraneoplastic and non-paraneoplastic retinopathy and optic neuropathy: Evaluation and management

Paraneoplastic syndromes involving the visual system are a heterogeneous group of disorders occurring in the setting of systemic malignancy. Timely recognition of one of these entities can facilitate early detection and treatment of an unsuspected, underlying malignancy, sometimes months before it would have otherwise presented, and gives the patient an increased chance at survival. We outline the clinical features, pathogenesis, and treatment strategies for the retinal- and optic nerve–based paraneoplastic syndromes: cancer-associated retinopathy; melanoma-associated retinopathy; paraneoplastic vitelliform maculopathy; bilateral diffuse uveal melanocytic proliferation; paraneoplastic optic neuropathy; and polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome. Distinguishing these disorders from their non-paraneoplastic counterparts (e.g., autoimmune-related retinopathy and optic neuropathy, and acute zonal occult outer retinopathy) and determining appropriate systemic evaluation for the responsible tumor can be challenging. In addition, we discuss the utility and interpretation of autoantibody testing.     

Sensitivity to first- and second-order motion and form in children and adults

We compared the sensitivity of adults and children aged 3-10 years to first- and second-order motion and form. For first-order stimuli, at all ages sensitivity was better for motion than form, and motion thresholds were better at 6 Hz than at 1.5 Hz. For second-order stimuli, at all ages sensitivity was better for form than motion, and motion thresholds were better at 0.25 cyc/deg than at 1 cyc/deg. Thresholds became adult-like later for motion than for form and later for first-order than second-order stimuli. For first-order stimuli, the changes with age were larger and more protracted.     

Nodes and nodal points and lines in eyes and other optical systems

The typical stigmatic optical system has two nodal points: an incident nodal point and an emergent nodal point. A ray through the incident nodal point emerges from the system through the emergent nodal point with its direction unchanged. In the presence of astigmatism nodal points are not possible in most cases. Instead there are structures, called nodes in this paper, of which nodal points are special cases. Because of astigmatism most eyes do not have nodal points a fact with obvious implications for concepts, such as the visual axis, which are based on nodal points. In order to gain insight into the issues this paper develops a general theory of nodes which holds for optical systems in general, including eyes, and makes particular allowance for astigmatism and relative decentration of refracting elements in the system. Key concepts are the incident and emergent nodal characteristics of the optical system. They are represented by 2 × 2 matrices whose eigenstructures define the nature and longitudinal position of the nodes. If a system's nodal characteristic is a scalar matrix then the node is a nodal point. Otherwise there are several possibilities: Firstly, a node may take the form of a single nodal line. Second, a node may consist of two separated nodal lines reminiscent of the familiar interval of Sturm although the nodal lines are not necessarily orthogonal. Third, a node may have no obvious nodal line or point. In the second and third of these classes one can define mid-nodal ellipses. Astigmatic systems exist with nodal points and stigmatic systems exist with no nodal points. The nodal centre may serve as an approximation for a nodal point if the node is not a point. Examples in the Appendix , including a model eye, illustrate the several possibilities.     

Nutritional antioxidants and age-related cataract and maculopathy

Loss of vision is the second greatest, next to death, fear among the elderly. Age-related cataract (ARC) and maculopathy (ARM) are two major causes of blindness worldwide. There are several important reasons to study relationships between risk for ARC/ARM and nutrition: (1) because it is likely that the same nutritional practices that are associated with prolonged eye function will also be associated with delayed age-related compromises to other organs, and perhaps, aging in general, (2) surgical resources are insufficient to provide economic and safe surgeries for cataract and do not provide a cure for ARM, and (3) there will be considerable financial savings and improvements in quality of life if health rather than old age is extended, particularly given the rapidly growing elderly segment of our population. It is clear that oxidative stress is associated with compromises to the lens and retina. Recent literature indicates that antioxidants may ameliorate the risk for ARC and ARM. Given the association between oxidative damage and age-related eye debilities, it is not surprising that over 70 studies have attempted to relate antioxidant intake to risk for ARC and ARM. This article will review epidemiological literature about ARC and ARM with emphasis on roles for vitamins C and E and carotenoids. Since glycation and glycoxidation are major molecular insults which involve an oxidative stress component, we also review new literature that relates dietary carbohydrate intake to risk for ARC and ARM. To evaluate dietary effects as a whole, several studies have tried to relate dietary patterns to risk for ARC. We will also give some attention to this emerging research. While data from the observational studies generally support a protective role for antioxidants in foods or supplements, results from intervention trials are less encouraging with respect to limiting risk for ARC/ARM prevalence or progress through antioxidant supplementations, or maintaining higher levels of antioxidants either in diet or blood. Without more information it is difficult to parse these results. It would be worthwhile to determine why the various types of studies are not yielding similar results. However, there are many common insults and mechanistic compromises that are associated with aging, and proper nutrition early in life may address some of these compromises and provide for extended youthful function later in life. Indeed, proper nutrition, possibly including use of antioxidant supplements for the nutritionally impoverished, along with healthy life styles may provide the least costly and most practical means to delay ARC and ARM. Further studies should be devoted to identifying the most effective strategy to prevent or delay the development and progress of ARC/ARM. The efforts should include identifying the right nutrient(s), defining useful levels of the nutrient(s), and determining the age when the supplementation should begin.     

Ethics and optometry: concepts and applications

Ethics refers both to the study of behaviour, and moral principals. The related concepts of justice and law are also relevant to optometry. A profession typically claims specialist knowledge and ethical behaviour – putting the interests of clients above its own. However, professional codes fail as ethical directives, and their goals are questioned. Beginning with broad principles, institutional ethics and issues of general health care provision are considered, and applications to optometry are made. Ethical theory can guide us in interacting with our patients, utilising resources and ordering priorities. The conservative approach to consumerism and advertising is defended on the basis of protecting public and professional interests. Ethical behaviour can be fostered, and this process should begin in undergraduate education.     

Exogenous attention and color perception: performance and appearance of saturation and hue

Exogenous covert attention is an automatic, transient form of attention that can be triggered by sudden changes in the periphery. Here we test for the effects of attention on color perception. We used the methodology developed by Carrasco, Ling, and Read [Carrasco, M., Ling, S., & Read, S. (2004). Attention alters appearance. Nature Neuroscience, 7 (3) 308-313] to explore the effects of exogenous attention on appearance of saturation (Experiment 1) and of hue (Experiment 2). We also tested orientation discrimination performance for single stimuli defined by saturation or hue (Experiment 3). The results indicate that attention increases apparent saturation, but does not change apparent hue, notwithstanding the fact that it improves orientation discrimination for both saturation and hue stimuli.     

晶状体细胞与信号转导和通讯

细胞信号转导和通讯在维持细胞的正常发育、增殖、分化、代谢及死亡中起到关键作用,是近几年研究的热点。本文对晶状体细胞信号转导系统中的信号、受体、主要转导通路和细胞通讯,以及它们的异常与白内障的关系进行综述,以期对白内障的发病机制作深入研究,为白内障的药物防治提供新的研究方向。