短波视蛋白在豚鼠频闪光诱导性近视和形觉剥夺近视眼模型中的表达差异

目的观察豚鼠频闪光诱导性近视和形觉剥夺近视模型中短波视蛋白(S-opsin)表达差异,并初步探讨原因。方法 36只普通级2周龄豚鼠随机分成三组:频闪组(FLM组,n=13),形觉剥夺组(FDM组,n=12),对照组(n=11)。FLM组,饲养笼具安装有频闪仪(频率0.5 Hz),笼具内装有发光二极管;FDM组豚鼠右眼用半透明眼罩遮盖,并确保豚鼠眼睑能正常活动;对照组豚鼠不予特殊处理。在造模第1天(0周)和第6周测量豚鼠右眼屈光度、眼轴长度和角膜曲率半径,并通过免疫荧光法观察S-opsin表达。结果第0周,FLM、FDM组与对照组屈光度、眼轴长度、角膜曲率半径差异均无显著性(P0.05)。造模6周后,与对照组相比,FLM组、FDM组屈光度变化值、眼轴长度变化值差异均有显著性(P0.05),而角膜曲率半径变化值差异无显著性(P=0.358),提示成功建立近视模型。FLM组与FDM组相比,屈光度变化值、眼轴长度变化值、角膜曲率半径变化值差异均无显著性(P0.05)。免疫荧光结果显示:FLM组视蛋白灰度值对照组视蛋白灰度值FDM组视蛋白灰度值,任意两组进行比较,差异均有显著性(P0.001)。结论频闪光和形觉剥夺均能建立近视模型,频闪光诱导性近视模型中S-opsin产生增加,而形觉剥夺性近视模型中S-opsin产生减少,说明两种近视模型的发生机制可能不同。     

530nm单色光诱导豚鼠近视眼模型的建立

目的应用530 nm单色光光照建立一种新型近视眼动物模型。方法20只约2周龄健康雄性豚鼠,随机分成两组（n=10）,实验组和对照组分别在绿光（530 nm）和白光（色温5000 k）下进行饲养。设置照明参数：光量子数相同,为每秒3×10-4μmol/cm2;实测光强度绿光为0.150 mW/cm2,白光为0.247 mW/cm2。实验前每组进行眼球生物学测量（屈光度、角膜曲率、眼轴各部分长度）,光照后12周重复测量以上数据,每只豚鼠均取右侧眼参数进行统计分析。结果光照前两组生物学测量参数差异无显著性。光照12周后,绿光组屈光度发生-3.125±0.76 D的变化,白光组为-1.075±0.71D,绿光组同对照白光组相比平均形成约2.0 D的近视,差异有显著性;绿光组眼轴和玻璃体腔分别增长0.98±0.13 mm与0.33±0.14 mm,对照组分别为0.77±0.22 mm与0.13±0.14 mm,绿光组较对照组眼轴和玻璃体腔长度延长较快,差异有显著性;光照后两组角膜曲率半径、前房深度和晶状体厚度均发生不同程度增加,但两组间变化差异无显著性。结论530 nm单色光诱导豚鼠眼球眼轴和玻璃体腔长度延长较快,产生近视.     

频闪光诱导光觉异常性豚鼠近视模型

目的使用特制的频闪调光器进行持续频闪光刺激,建立一种光觉异常性豚鼠近视模型,观察豚鼠在频闪光刺激后眼球产生的异常改变。方法 24只2周龄普通级豚鼠随机分为3组(n=8),Ⅰ组予0.5 Hz频率等时交替频闪,频闪亮度0～600 lx;Ⅱ组为无频闪等亮度光照组;Ⅲ组为开放环境正常光照组。光照时间6∶00～18∶00。每2周记录屈光度、眼轴长度及曲率半径,12周时眼底拍照后取出眼球,光学显微镜及扫描电镜观察眼球后极部改变。结果光照前各组间生物学测量参数差异无显著性(P>0.05)。随时间延长,Ⅰ组与Ⅱ、Ⅲ组相比近视屈光度明显增加、眼轴延长,12周时3组间近视屈光度及眼轴差异有显著性(P<0.05),Ⅰ组与Ⅱ组相比眼球发生(-5.4±1.5)D的近视,眼轴增加(0.74±0.18)mm。Ⅰ组与Ⅲ组相比眼球发生(-6.6±1.5)D的近视,眼轴增加(0.86±0.24)mm。Ⅰ组眼底普遍出现豹纹状改变,视网膜感觉细胞层外段排列紊乱且有大量脱落节盘。结论通过改变正常光觉环境,频闪光能刺激豚鼠眼球产生过度发育并诱导轴性近视形成。这种光觉的异常最终影响了视网膜感光细胞的正常发育。     

小空间细颗粒饲养对青少年恒河猴屈光发育及玻璃体腔长度变化的影响

采用小空间细颗粒饲养方法研究长时间近距离注视对青少年恒河猴屈光状态发育和玻璃体腔长度变化的影响. 将12只1.5~2.0岁健康恒河猴随机分为三组, 每组四只. 其中A组和B组每天分别置于视觉封闭的猴笼内饲养8和4 h, 同时将食物处理成细小颗粒状置于代谢盘中(需仔细翻找才能获得). 每3个月进行一次眼轴长度、玻璃体腔长度、屈光状态和角膜曲率测量, 总观察周期为18个月. 采用对照t检验进行数据分析, P<0.05有显著性意义. 结果显示, 观察期间A组眼轴和玻璃体腔长度增长最为显著, 屈光状态明显向近视化方向发展; B组眼轴和玻璃体腔长度也有明显增长, 但屈光度无明显变化; C组眼轴和玻璃体腔长度增长最为缓慢, 屈光度轻度向远视化方向发展. 观察期间各组的角膜曲率均无明显改变. 研究结果表明, 强制性近距离注视能够加快青少年恒河猴玻璃体腔长度的增长, 导致单纯性近视的发生与发展, 是建立近距离工作相关的灵长类近视眼动物模型的可行性方法.     

调整非球面因子的近视矫正模型及仿真

针对人眼角膜形状的非球面性,给出了以非球面因子为参数的二次曲面来对角膜表面建模,以此推导了近视矫正量公式,给出各参数的确定方法。与球面假设的近视模型比较,在相同术区大小和矫正近视度数的情况下,非球面假设的近视矫正模型可减小角膜最大切削深度。本模型保证了正常角膜的非球性,理论上可减少术后球差,改善术后视觉质量;本模型可用于指导单纯近视的矫正。     

光学相干断层成像术在近视眼视网膜神经纤维层厚度测量中的临床应用

目的:研究光学相干断层成像术(OCT)在近视眼视网膜神经纤维层(RNFL)厚度测量中的应用价值。方法:选择2016年1月到2016年5月在医院就诊的近视患者73例(138眼)纳入此次研究,根据近视情况将患者分为低度近视组(-0.30D~-3.00D)共26例(48眼)、中度近视组(-3.01~-6.00D)共24例(47眼)及高度近视组(-6.00D)共23例(43眼)。另选同期在医院体检(视力正常)的健康志愿者25例(45眼)作为对照组,对比各组不同象限的RNFL厚度,屈光度及眼轴长度,分析近视眼各象限的RNFL厚度与患者屈光度和眼轴长度的相关性。结果:高度近视组的上方象限、下方象限以及鼻侧象限的RNFL厚度均明显低于对照组及中度近视组,中度近视组的下方象限及鼻侧象限的RNFL厚度均明显低于对照组,低度近视组鼻侧象限的RNFL厚度明显低于对照组,差异均有统计学意义(均P0.05)。近视组的屈光度及眼轴长度均明显大于对照组,且高度近视组均明显大于中度近视组与低度近视组,中度近视组均明显大于低度近视组,差异均有统计学意义(均P0.05)。根据Pearson法分析相关性可知,近视眼患者上象限、下象限、鼻侧象限的RNFL厚度与其屈光度及眼轴长度均呈负相关。结论:利用OCT技术检测近视眼RNFL厚度时,应考虑屈光度及眼轴长度可能造成的影响,综合进行分析判断,以获得最佳检测数值。     

短波长单色光对豚鼠眼屈光发育的影响

目的研究短波长单色光对豚鼠的屈光发育和眼生物学参数的影响。方法 20只出生约2周的健康雄性豚鼠,随机分成两组（n=10）,分别在蓝光（430 nm）和白光（色温5000 K）下进行饲养。蓝光组为实验组,白光组为对照组,实验周期为12周。两种光照的光量子数均为每秒3×10-4μmol/cm2,测量光强度蓝光为0.527mW/cm2,白光为0.247 mW/cm2。实验前后均进行屈光度、角膜曲率、眼轴各部分长度的测量。结果实验前两组测量参数差异无显著性（P〉0.05）。光照12周后,蓝光组屈光度增加（1.20±0.66）D,白光组减少（1.18±0.85）D,蓝光组与白光组相比平均形成约2.40 D远视,统计学差异显著（P〈0.0001）;蓝光组眼轴和玻璃体腔分别增长（0.77±0.12）mm与（0.05±0.10）mm,白光组分别增长（0.95±0.18）mm与（0.21±0.13）mm。蓝光组的眼轴和玻璃体腔长度增长较白光组慢（P〈0.05）。但实验后两组角膜曲率半径、前房深度和晶状体厚度的变化差异无显著性（P〉0.05）。结论 430 nm短波长单色光诱导豚鼠眼轴和玻璃体腔长度延长较慢,产生远视。     

豚鼠眼形觉剥夺后恢复期的生物学参数变化规律探讨

目的探讨豚鼠眼球形觉剥夺后恢复期的生物学参数变化规律。方法普通级2～3周龄豚鼠30只,随机分为两组：①实验组：20只,右眼采用半透明眼罩遮盖进行形觉剥夺4周,随后去遮盖3周,左眼作为自身对照;②正常对照组：10只,双眼不进行任何干预,开放饲养7周。形觉剥夺前、形觉剥夺4周后及去遮盖后第2、6、10、14和21天,测量豚鼠双眼生物学参数：睫状肌麻痹后行带状光检影测量屈光度;A超测量前房深度、晶体厚度和眼轴长度,计算出玻璃体腔长度。结果经过4周形觉剥夺,实验组豚鼠右眼向近视漂移,屈光度为（-2.88±2.30）D,诱导了（-5.50±1.9）D相对近视。去遮盖后,豚鼠右眼重新正视化,屈光度恢复的快速期发生在6 d内,14 d时双眼屈光度差值差异无显著性（t=-2.049,P=0.080）,为（-0.18±0.26）D;右眼玻璃体腔长度缩短,14 d时双眼玻璃体腔长度差值差异无显著性（t=1.652,P=0.14）,为（0.0234±0.0400）mm;右眼眼轴长度缩短,14 d时双眼眼轴长度差值差差异无显著性（t=1.443,P=0.192）,为（0.0183±0.0359）mm。与正常对照组右眼相比,去遮盖6 d,屈光度差异为（-0.48±0.36）D,差异无显著性（t=-1.325,P=0.206）,而2 d时玻璃体腔和眼轴长度差异分别为（0.0961±0.0630）mm、（0.0621±0.0386）mm,差异无显著性（t=1.652,P=0.14;t=1.607,P=0.125）。结论 2～3周龄豚鼠去除形觉剥夺后可以重新进行正视化,伴随玻璃体腔和眼轴长度缩短;去遮盖6 d内为眼生物学参数恢复的主要时期。     

屈光度和眼轴长度对豚鼠视网膜神经纤维层厚度和视乳头形态的影响

目的使用光学相干断层扫描(optical coherence tomography,OCT)观察豚鼠视网膜神经纤维层(retinal nerve fiber layer,RNFL)厚度及视乳头形态,并探讨豚鼠等效球镜和眼轴长度与这些参数的相关性。方法选用20只普通级豚鼠,进行等效球镜和眼轴长度测量,以及运用OCT观察豚鼠RNFL厚度及视乳头形态。结果豚鼠等效球镜与RNFL平均厚度、上方RNFL厚度、颞侧RNFL厚度、下方RNFL厚度、鼻侧RNFL厚度呈正相关;而眼轴长度与RNFL平均厚度、上方RNFL厚度、颞侧RNFL厚度、下方RNFL厚度、鼻侧RNFL厚度呈负相关。等效球镜和眼轴长度与盘沿面积、视盘面积、平均杯盘比、杯容积无相关性。等效球镜和垂直杯盘比无相关性,而眼轴长度与垂直杯盘比存在正相关。结论等效球镜和眼轴长度对豚鼠各方位RNFL厚度均有影响。在使用豚鼠作为高眼压动物模型时,需考虑其屈光状态和眼轴长度的影响。     

江豚眼折光系统的初步研究

本文对江豚(Neomeris phocaenoides)眼折光系统的各个组成部分——角膜、前房水、晶状体和玻璃体进行了解剖学和光学参数的测量.对江豚简约眼的各项光学参数进行了计算.根据解剖学测量和简约眼的计算结果对江豚眼的折射状态作了估计.结果表明,江豚眼角膜的曲率较小其折光能力较弱,而其晶状体的折光能力却较强,在眼的折光系统中起着主要作用.江豚眼的折射误差(refractive error)为-25.1D,,说明江豚为高度近视眼,只有当物体靠得很近时,江豚的视觉才起作用.文章把江豚眼折光系统的实验结果与某些陆生哺乳动物的实验结果作了比较,讨论了水生哺乳动物与陆生哺乳动物眼折光系统的某些差别.     

The measurement of ocular axial length in normal human eyes based on an improved Twyman-Green interferometer

In order to meet the demands of myopia prevention, as well as the increasing needs of measurement for refractive and cataract operations in China, a new axial length (AL) measurement system combining an improved Twyman-Green interferometer with digital signal processing has been established. The ALs of 33 eyes of different optical refractive subjects (−8.50 ~ 0.50 D) were measured with the New AL and intraocular lens (IOL) master. The repeatability of measurements with the New AL was assessed using coefficient of variation (CoV) and intra-group correlation coefficient (ICC). Comparison, correlation, linear regression and agreement of AL between devices were analyzed. There was good repeatability (CoV = 0.0617%, ICC = 0.9999) with the New AL and great agreement has been obtained with both devices. These show that the New AL is capable of providing precise AL values over the normal AL range compared to the IOL master, and indicate that the New AL developed can be used for routine clinical AL measurements.     

Sources of variation affecting cashmere grown in the Pamir mountain districts of Tajikistan and implications for industry development

We aimed to quantify the sources of variation contributing to the main quality attributes of cashmere produced from goats in the Pamir mountain districts of Murghab, Shugnon and Vanj in Tajikistan. In early spring 2010, mid-side samples were taken from 194 adult females, 43 adult males and 20 castrates belonging to 58 farmers and pastoralists in 14 villages. For 57 goats, samples were also taken from the shoulder and hip sites. Mean fibre diameter (MFD), fibre curvature (FC) and cashmere staple length (SL) data were examined using a general linear model to determine the relationships between fleece attributes and other possible effects. For females, the mean (s.d.) for MFD, FC and SL were: 16.5 (1.70) μm; 46 (12.1)°/mm; 53 (22.9) mm. MFD was affected by district, SL and age of goat. SL was affected by district, MFD, gender, age of goat and village. FC was affected by district, MFD, shade of cashmere, age of goat and farmer. Cashmere from Vanj district was finer and shorter than cashmere from Murghab and Shugnon. Cashmere grown on the mid-side and hip sites was finer and had higher FC than cashmere grown on the shoulder. Cashmere grown on the hip was shorter than cashmere grown on the mid-side and shoulder. About 50% of the cashmere sampled was < 16.4 μm and potentially suitable for knitwear. Of this fine cashmere, 53% was 34 mm or longer. A further 37% of the cashmere was 16.4-18.5 μm, and suitable for weaving as 97% was longer than 36 mm. Almost 12% of samples were > 18.5 μm and may only be suitable for weaving or, if cashgora, will have little commercial value. Most of the cashmere was coloured. There are cashmere goats in the Murghab, Shugnon and Vanj districts of Tajikistan which produce the finest qualities of cashmere, comparable to premium grades of Chinese cashmere. There is substantial scope to increase the commercial value of cashmere produced by goats in Tajikistan, in particular increasing SL for fine cashmere, reducing MFD for the longest cashmere and ensuring cashmere has acceptable FC and white colour.     

Swelling of the collagen-keratocyte matrix of the bovine corneal stroma ex vivo in various solutions and its relationship to tissue thickness

AIM: The mammalian corneal stroma, like some other connective tissues, can absorb fluid, swell and become oedematous. Since studies on the corneal stroma have been carried out with different types of preparations and solutions, inter-study comparisons are very difficult. A study was thus undertaken on a standardised preparation to assess the relative magnitude of this swelling and its relationship to thickness of the preparations. METHODS: From selected recent post-mortem eyes of adult cattle, stroma preparations were cut from the central part of the cornea. These preparations were immersed in various solutions of known pH and osmolality, and the time-dependent changes in wet mass were assessed over 9 h at 37 degrees C. The relative rates and magnitude of the swelling of the tissue were then compared. RESULTS: A reference value for stromal swelling was obtained by incubation in a 35 mM bicarbonate-buffered mixed salts solution equilibrated with 5% CO2-air (pH 7.60) where a 3.39-fold increase in wet mass and a 4.58-fold increase in thickness was realised in 9 h, at an initial rate of 76 +/- 3%/h. The swelling was essentially the same in an organic buffer-mixed salt solution (pH 7.5) but progressively greater in phosphate-buffered saline (pH 7.5), a range of phosphate buffers (10-67 mM, pH 7.5), NaCl solutions (0.025-1%) and with gross swelling observed in water (where a 15.9-fold increase in wet mass occurred along with a 25-fold increase in thickness, at an initial rate of 643 +/- 62%/h). Overall, the wet mass changes were strongly related to thickness (P < 0.001). CONCLUSIONS: The results confirm that the selection of solution(s) for studies on corneal stromal swelling is critical. The swelling (oedema) is lower in a physiologically-relevant solution (similar to the aqueous humour of the eye). This indicates that the swelling tendency of the corneal stroma has been overestimated in the past, and that a similar discrepancy may also exist for studies on other connective tissues ex vivo when non-physiological experimental solutions are used.     

Contribution of the intrinsic curvature to measured DNA persistence length

The persistence length of DNA, a, depends both on the intrinsic curvature of the double helix and on the thermal fluctuations of the angles between adjacent base-pairs. We have evaluated two contributions to the value of a by comparing measured values of a for DNA containing a generic sequence and for an "intrinsically straight" DNA. In each 10 bp segment of the intrinsically straight DNA an initial sequence of five bases is repeated in the sequence of the second five bases, so any bends in the first half of the segment are compensated by bends in the opposite direction in the second half. The value of a for the latter DNA depends, to a good approximation, on thermal fluctuations only; there is no intrinsic curvature. The values of a were obtained from measurements of the cyclization efficiency for short DNA fragments, about 200 bp in length. This method determines the persistence length of DNA with exceptional accuracy, due to the very strong dependence of the cyclization efficiency of short fragments on the value of a. We find that the values of a for the two types of DNA fragment are very close and conclude that the contribution of the intrinsic curvature to a is at least 20 times smaller than the contribution of thermal fluctuations. The relationship between this result and the angles between adjacent base-pairs, which specify the intrinsic curvature, is analyzed.     

Modulation of the Physical Properties of 3D Spheroids Derived from Human Scleral Stroma Fibroblasts (HSSFs) with Different Axial Lengths Obtained from Surgical Patients

In the current study, to elucidate the pathological characteristics of myopic scleral stroma, three-dimensional (3D) cultures of human scleral stroma fibroblasts (HSSFs) with several axial lengths (AL, 22.80–30.63 mm) that were obtained from patients (n = 7) were examined. Among the three groups of ALs, <25 mm (n = 2), 25–30 mm (n = 2), and >30 mm (n = 3), the physical properties of the 3D HSSFs spheroids with respect to size and stiffness, the expressions of extracellular matrix (ECM) molecules, including collagen (COL) 1, 4, and 6 and fibronectin (FN) by qPCR and immunohistochemistry (IHC), and the mRNA expression of ECM metabolism modulators including hypoxia-inducible factor 1A (HIF 1A), HIF 2A, lysyl oxidase (LOX), tissue inhibitor of metalloproteinase (TIMP) 1–4, and matrix metalloproteinase (MMP) 2, 9, and 14 as well as several endoplasmic reticulum (ER) stress-related factors were compared. In the largest AL group (>30 mm), the 3D HSSFs spheroids were (1) significantly down-sized and less stiff compared to the other groups, and (2) significant changes were detected in the expression of some ECMs (qPCR; the up-regulation of COL1 and COL4, and the down-regulation of FN, IHC; the up-regulation of COL1 and FN, and down-regulation of COL4). The mRNA expressions of ECM modulators and ER stress-related genes were also altered with increasing AL length (up-regulation of HIF2A, MMP2, XBP1, and MMP14, down-regulation of LOX, TIMP 2 and 3, GRP78, GRP94, IRE1, and ATF6). In addition, a substantial down-regulation of some ER stress-related genes (ATF4, sXPB1 and CHOP) was observed in the 25–30 mm AL group. The findings presented herein suggest that small and stiffer 3D HSSFs spheroids in the largest AL group may accurately replicate the pathological significance of scleral thinning and weakening in myopic eyes. In addition, the modulation of several related factors among the different AL groups may also provide significant insights into our understanding of the molecular mechanisms responsible for causing myopic changes in the sclera.     

Environmental monitoring through functional biodiversity tools

The foundational concept for our research, which is largely shared by statisticians and ecologists, is that biodiversity is one of the most important indicators for environmental assessment. Because this indicator decreases in relation to ecosystem stressors, its measurement is essential for predicting future biological impacts of environmental damages. Although many indices have been proposed, no universally accepted measure for biodiversity has yet been established. In this context, the use of diversity profiles allows the analyst to display a family of indices in a single graph. However, this approach presents two critical limitations: first, a community composition is not always interpretable; second, the diversity profiles could lead to ranking issues when the curves intersect each other. The aim of this paper is to resolve these limitations by introducing functional biodiversity tools. In particular, three functional measures are proposed: the derivatives, the radius of curvature and the curve length. The analysis of derivatives and of the radius of curvature addresses the first limitation and highlights the characteristics, the differences and the similarities among communities. Arc length addresses the second limitation, providing a scalar measure that leads to a unique communities ranking for a given pattern of richness even if profiles intersect. The proposed functional models are applied to a real data set involving lichen biodiversity in the province of Genoa, Italy. Our approach allowed us to analyze the characteristics of lichen communities and to identify the biodiversity ranking. The combined use of these tools provides a useful method for identifying areas of high environmental risk, with the potential to address the monitoring of environmental policies.     

光诱导角膜交联及检测技术的研究进展

由于圆锥角膜疾病导致越来越多的人患有近视,常见的矫正方法有佩戴近视眼镜、隐形眼镜等.随着科技的进步,利用光对近视等眼科疾病进行屈光矫正已经成为当前临床中常用的方法.使用光诱导角膜胶原蛋白发生交联,从而达到治疗圆锥角膜疾病、提高患者视力水平的目的,这是一种新型的光治疗眼睛疾病的方法.同时这种方法由于无侵入性、对操作者能力依赖性小等优势成为新的研究热点.本文阐述光诱导角膜交联的基本原理,并介绍其发展历程,分析现有的各种交联方法和角膜检测技术的原理,并对现有交联方法和检测方法的优缺点进行讨论.最后,本文对光诱导角膜交联和检测技术的最新进展进行系统的论述,并对未来的发展趋势进行展望.     

Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis

Application of the air‐puff swept source optical coherence tomography (SS‐OCT) instrument to determine the influence of viscoelasticity on the relation between overall the air‐puff force and corneal apex displacement of porcine corneas ex vivo is demonstrated. Simultaneous recording of time‐evolution of the tissue displacement and air pulse stimulus allows obtaining valuable information related in part to the mechanical properties of the cornea. A novel approach based on quantitative analysis of the corneal hysteresis of OCT data is presented. The corneal response to the air pulse is assessed for different well‐controlled intraocular pressure (IOP) levels and for the progression of cross‐linking‐induced stiffness of the cornea. Micrometer resolution, fast acquisition and noncontact character of the air‐puff SS‐OCT measurements have potential to improve the in vivo assessment of mechanical properties of the human corneas.      

Absence of corneal endothelium injury in non‐human primates treated with and without ophthalmologic drugs and exposed to 2.8 GHz pulsed microwaves

Microwave‐induced corneal endothelial damage was reported to have a low threshold (2.6 W/kg), and vasoactive ophthalmologic medications lowered the threshold by a factor of 10–0.26 W/kg. In an attempt to confirm these observations, four adult male Rhesus monkeys (Macaca mulatta) under propofol anesthesia were exposed to pulsed microwaves in the far field of a 2.8 GHz signal (1.43 ± 0.06 µs pulse width, 34 Hz pulse repetition frequency, 13.0 mW/cm² spatial and temporal average, and 464 W/cm² spatial and temporal peak (291 W/cm² square wave equivalent) power densities). Corneal‐specific absorption rate was 5.07 W/kg (0.39 W/kg/mW/cm²). The exposure resulted in a 1.0–1.2 °C increase in eyelid temperature. In Experiment I, exposures were 4 h/day, 3 days/week for 3 weeks (nine exposures and 36 h total). In Experiment II, these subjects were pretreated with 0.5% Timolol maleate and 0.005% Xalatan® followed by 3 or 7 4‐h pulsed microwave exposures. Under ketamine–xylazine anesthesia, a non‐contact specular microscope was used to obtain corneal endothelium images, corneal endothelial cell density, and pachymetry at the center and four peripheral areas of the cornea. Ophthalmologic measurements were done before and 7, 30, 90, and 180 days after exposures. Pulsed microwave exposure did not cause alterations in corneal endothelial cell density and corneal thickness with or without ophthalmologic drugs. Therefore, previously reported changes in the cornea exposed to pulsed microwaves were not confirmed at exposure levels that are more than an order of magnitude higher. Bioelectromagnetics 31:324–333, 2010. Published 2010 Wiley‐Liss, Inc.     

Effect of porcine corneal stromal extract on keratocytes from SMILE-derived lenticules

Propagating large amounts of human corneal stromal cells (hCSCs) in vitro while maintaining the physiological quality of their phenotypes is necessary for their application in cell therapy. Here, a novel medium to propagate hCSCs obtained from small incision lenticule extraction (SMILE)-derived lenticules was investigated and the feasibility of intrastromal injection of these hCSCs was assessed. Primary hCSCs were cultured in porcine corneal stroma extract (pCSE) with RIFA medium including ROCK inhibitor Y27632, insulin-transferrin-selenium, fibroblast growth factor 2, L-ascorbate 2-phosphate and 0.5% FBS (RIFA medium + pCSE). Protein profiling of the pCSE was identified using nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS). After subculturing in RIFA medium + pCSE or 10% FBS normal medium (NM), hCSCs at P4 were transplanted into mouse corneal stroma. Compared with NM, ALDH3A1, keratocan and lumican were significantly more expressed in the RIFA medium + pCSE. ALDH3A1 was also more expressed in the RIFA medium + pCSE than in the RIFA medium. Fibronectin and α-SMA were less expressed in the RIFA medium + pCSE than in the NM. Using Metascape analysis, the pCSE with its anti-fibrosis, pro-proliferation and anti-apoptosis activities, was beneficial for hCSC cultivation. The intrastromally implanted hCSCs in the RIFA medium + pCSE had positive CD34 expression but negative CD45 expression 35 days after injection. We provide a valuable new medium that is advantageous for the proliferation of hCSCs with the properties of physiological keratocytes. Intrastromal injection of hCSCs in RIFA medium + pCSE has the potential for clinical cell therapy.