Cataracts: Clinical presentations,diagnosis and management

Cataracts can be developmental or acquired lesions and cause minimal or significant visual impairment. The ability to identify cataracts and determine the likely effect on the visual potential of the horse is an important part of an equine ocular examination. Cataract surgery is the only treatment for those cataracts that cause significant visual impairment. Understanding appropriate patient selection and potential post operative complications is important so that owners can be appropriately advised of their options.     

Three-dimensional study on the effect of organophosphate pesticide 'monocrotophos' on lens of fish and its recovery

The present studies are based on the feedback provided by fish farmers practicing composite fish culture of carps. According to them, fish habitats are affected by pesticides draining from agricultural fields into their catchments, especially during the rainy season. The lenses of most of the cultured fish became opaque, resulting in poor overall growth. In the literature, there was mounting evidence of pesticide toxicity involving multiple tissues. However, the fish visual system has never been investigated particularly from the toxicological perspective. In this regard, we carried out comparative toxicological studies on the lens of Cyprinus carpio communis using three different sublethal concentrations (0.038, 0.062 and 0.126 p.p.m.) of monocrotophos along with untreated controls for 30 days. Lenses from all the groups were extracted and preserved in gluteraldehyde and osmium tetraoxide and dehydrated in increasing grades of acetone. After dehydration, tissues were conducted with gold to observe under SEM. The fish exposed to monocrotophos developed cataract. Furthermore, when fish from the monocrotophos-treated tanks were transferred to normal environmental conditions for the next 60 days, progressive lens degeneration was noted. To conclude, monocrotophos induces irreversible cataractous changes in the lens of C. carpio communis . The fish visual system has many similarities to mammals and may serve as a good model for comparative toxicologic and ophthalmologic studies.     

共聚物水凝胶接触镜材料中氧气渗透及其影响因素

以N-乙烯吡咯烷酮(NVP)、甲基丙烯酸2-羟乙酯(HEMA)以及甲基丙烯酸甲酯(MMA)、甲基丙烯酸乙酯(EMA)或甲基丙烯酸丁酯(BMA)为原料,制备共聚物水凝胶角膜接触镜材料,分析了氧气在水凝胶膜中的渗透机理,建立了氧气在水凝胶膜中的扩散模型,并采用等压渗透法测定了水凝胶膜的透氧性能.结果表明,氧气在水凝胶膜中的扩散过程同时受到水凝胶中结合水水分子、自由水水分子以及高聚物大分子链无规则热运动的影响,但水凝胶中结合水水分子和高聚物大分子链的无规则热运动对氧气分子扩散行为的影响可以忽略不计;氧气分子在水凝胶中的扩散行为主要受水凝胶中自由水水分子无规则热运动的影响;水凝胶膜的交联网络结构对氧气的扩散过程起过滤作用.在一定范围内,温度越高、含水量越大、交联密度越低,共聚物水凝胶接触镜材料的透氧性能越高.     

基于数码显微目镜传递系统的皮肤科远程会诊系统设计与实现

本研究采用普通光镜加装数码显微目镜系统后,使其具有数码功能,再由计算机接收、存储、显示和分析显微图像,装配成医学显微图像数字化系统,实现了对皮肤科实验室中性传播疾病病原体的检测、真菌的鉴定和皮肤病理显微图像的数字化处理,并借助网络平台进行远程实时传递实施皮肤科实验室病原微生物检查项目和病理片的远程会诊,使用方便、效果理想、价格低廉、便于推广。     

新疆虹鳟贝氏复口吸虫的空间分布

为了解贝氏复口吸虫(Diplostomum baeri)在虹鳟(Oncorhynchus mykiss)眼部寄生的空间分布特点,2017年4次对新疆博尔塔拉蒙古自治州温泉县冷水鱼繁育基地的虹鳟进行采样调查,运用统计学方法对虹鳟眼睛寄生贝氏复口吸虫的空间分布特点进行分析。结果显示,在检查的61尾虹鳟中,检出贝氏复口吸虫9 023只,单尾检出最多为388只。总感染率为100%,左右眼玻璃体的感染率为100%和96.7%,高于左右眼晶状体的感染率60.7%和42.6%。总平均感染强度为(147.9±11.6),左右眼玻璃体平均感染强度为(90.9±6.7)和(71.9±6.1),高于左右眼晶状体平均感染强度(7.4±1.9)和(7.0±2.1)。左眼和右眼的平均感染强度无统计学差异(P0.05),晶状体和玻璃体的平均感染强度差异极显著(P0.01)。贝氏复口吸虫在虹鳟不同部位的方均比(S~2/■)大于1,说明贝氏复口吸虫对该地虹鳟的寄生情况严重,在虹鳟的不同部位中均呈聚集性分布,更倾向于在玻璃体中寄生,存在寄生部位选择偏好性。     

青年人晶状体悬韧带弹性的实验研究

目的 :探讨青年人晶状体悬韧带的弹性。方法 :将晶状体进行开放性环形撕囊 ,清除晶状体皮质 ,经巩膜壁向玻璃体腔注入生理盐水以增加玻璃体腔的压力 ,测量晶状体悬韧带的伸展数据。结果 :2 1例 (42只眼 )晶状体悬韧带长 1 .0 0～ 1 .50 mm,平均 (1 .30±0 .2 2 ) mm,晶状体悬韧带伸长达 4.50～ 6.50 mm,平均 (5.2 1± 0 .72 ) mm。结论 :青年人晶状体悬韧带有较强的弹性。     

左手材料参数偏移对其传输函数的影响

根据电磁场理论推导出了左手材料的传输函数,并数值计算了介电常数和磁导率偏移理想值时,传输函数所发生的变化.数值计算表明:传输函数对介电常数和磁导率的偏移非常敏感,完美的左手材料透镜对偏移量的要求十分苛刻.因此,要得到工程意义上完美的左手材料透镜是相当困难的.     

一种精确测定X光透镜发散度的实验方法

为了建立精确测定X光透镜发散度的实验方法,提出了有效X光源的概念,这样可以得到X光束发散度的准确值．推导出了X光束发散度的理论计算公式．零点扫描实验方法证明了理论公式的正确性．晶体转动实验方法测量了X光束的发散度,与理论值符合得很好,晶体转动实验方法建立．晶体转动实验方法应用到对X光透镜发散度的测定可以消除分析晶体不完整性的影响,精确性很高．