蓝光与视功能关系的研究进展

光线是人眼形成视觉的重要条件之一.研究发现蓝光与眼的关系密切,蓝光通过视网膜感光神经节细胞对人类调节昼夜节律有作用,蓝光也可造成视网膜光损伤.本文就蓝光与眼病的关系及为避免蓝光对眼的损害在人工晶状体设计等方面的进展作一综述.     

蓝光与视功能关系的研究进展

光线是人眼形成视觉的重要条件之一.研究发现蓝光与眼的关系密切,蓝光通过视网膜感光神经节细胞对人类调节昼夜节律有作用,蓝光也可造成视网膜光损伤.本文就蓝光与眼病的关系及为避免蓝光对眼的损害在人工晶状体设计等方面的进展作一综述.     

蓝光及蓝光滤过型人工晶状体对体外培养人视网膜色素上皮细胞的影响

目的探讨蓝光滤过型人工晶状体（intraocular lens，IOL）对含N-亚视黄基-N-视黄基乙醇胺（A2E）的人视网膜色素上皮（retinal pigment epithelium，RPE）细胞的细胞活力、氧化应激及分泌血管内皮生长因子（vascular endothe-lial growth factor，VEGF）、色素上皮衍生因子（pigment epithelium detived factor，PEDF）的影响。方法体外培养含A2E的RPE细胞，用低强度蓝光持续照射，在光通路上置蓝光滤过型（AcrySof Natural）或紫外线阻挡型（AcrySof）IOL。细胞分为：A组（AcrySof Natural IOL，光照）；B组（AcrySof IOL，光照）；C组（光照，无IOL）；D组（无光照，无IOL）。CCK-8检测细胞活力，流式细胞仪检测活性氧自由基（reactive oxygen species，ROS）水平，酶联免疫吸附法检测还原型谷胱甘肽（glutathione，GSH）、VEGF、PEDF含量。结果A、B、C和D组细胞活力分别为（76.9±3.9）％、（42.5±4.3）％、（35.2±4.1）％、（96.7±3.1）％；ROS分别为511.53±67.43、1011.15±174.88、1022.23±158.72、452.82±77.98：GSH分别为（15.34±4.77）μmol／L、（2.57±1.96μmol/L、（1.58±1.13）μmol/L、（19.73±5.49）μmol／L；VEGF／PEDF比值分别为1.40、9.76、14.86、0.71。同B、C组相比，A组细胞活力和GSH含量明显提高，ROS含量和VEGF／PEDF比值明显下降（P〈0.05）。结论蓝光滤过型IOL对A2E介导的RPE细胞蓝光损伤有保护作用，能够降低蓝光诱导的ROS和VEGF水平，优于紫外线阻挡型IOL。     

铁死亡在年龄相关性黄斑变性中的调控机制研究进展

目的 铁死亡是一种以脂质过氧化为特征的调节性细胞死亡,在年龄相关性黄斑变性(AMD)中扮演重要角色。本文就AMD的病理机制、铁死亡过程及特征进行回顾,并从铁离子代谢途径、胱氨酸/谷氨酸逆向转运体途径、脂质代谢途径、核转录因子途径、自噬依赖性途径及免疫相关途径对铁死亡在AMD发生发展中的调控机制进行论述,最后归纳总结部分铁死亡抑制剂对视网膜色素上皮细胞的保护作用,为AMD的治疗提供新的思路。     

视网膜色素上皮细胞移植研究进展及存在的问题

近年来,视网膜色素上皮(RPE)细胞移植在治疗年龄相关性黄斑变性等疾病方面取得了一些进展。移植细胞根据来源和类型分为自体RPE细胞、自体虹膜色素上皮细胞、异体胎儿RPE细胞、异体成人RPE细胞、胚胎干细胞衍生的RPE细胞、诱导多能干细胞衍生的RPE细胞;根据移植方式分为RPE细胞悬液移植和RPE细胞片移植。自体RPE细...     

诱导多能干细胞治疗年龄相关性黄斑变性的研究进展

年龄相关性黄斑变性是造成中老年人失明的主要原因,严重影响了患者的生活质量,但目前尚无有效疗法。随着病情的进展,视网膜色素上皮层细胞逐渐退化,并最终引起视力的不可逆性损害。诱导多能干细胞的出现提供了可供移植的视网膜色素上皮细胞来源,避免了免疫及伦理等问题,但仍然需要克服许多障碍和困难。     

丛生蛋白参与年龄相关性黄斑变性的作用机制

丛生蛋白是玻璃膜疣的主要蛋白成分之一。近年来研究发现丛生蛋白与衰老密切相关,不仅通过对补体系统的调节参与年龄相关性黄斑变性（ａｇｅ-ｒｅｌａｔｅｄｍａｃｕｌａｒｄｅｇｅｎ-ｅｒａｔｉｏｎ,ＡＭＤ）炎症反应发生机制,也与氧化还原反应密切相关,是ＡＭＤ发生过程中氧化应激反应的感受器。本文就丛生蛋白参与ＡＭＤ作用机制的研究进展进行综述。     

视网膜色素上皮细胞氧化应激相关microRNA的鉴定

目的：应用miRNA表达谱芯片筛选视网膜色素上皮细胞与氧化应激相关的miRNA,为更加全面深入地研究年龄相关性黄斑病变(age-related macular degeneration,AMD)发生的分子机制提供新的思路。

方法：培养D407细胞,分别使用100、200、400μmol/L H₂O₂处理细胞24h后,Trizol试剂抽提细胞总RNA,使用Exiqon miRCURY LNA^TM microRNA表达谱芯片(miRBase 16.0数据库)检测不同浓度处理后D407细胞miRNA的表达差异,并将不同浓度处理后的变化进行聚类分析。使用Stem loop realtime PCR对芯片结果进行验证,并运用生物信息学方法预测差异miRNA调控的靶基因。

结果：芯片所包含的1 425个已知miRNA中,共有367个在不同浓度H₂O₂处理后表达发生变化。通过Treeview软件进行聚类分析发现miR-31等17个miRNA随H₂O₂浓度的升高呈现逐渐降低的趋势,miR-206等7个则逐渐升高。PCR验证显示芯片结果准确性较好。

结论：H₂O₂作用前后RPE的miRNA表达存在明显差异,miRNA作为转录后水平的调节分子,参与了细胞氧化应激反应,可能在AMD的发生发展中起有重要作用。     

干性ARMD中视网膜色素上皮细胞的作用及损伤机制

年龄相关性黄斑变性(age-related macular degeneration,ARMD)是导致老年人中心视力不可逆丧失的主要原因。ARMD的典型特征是视网膜色素上皮(retinal pigment epithelium,RPE)和脉络膜毛细血管发生退行性改变及黄斑区出现玻璃膜疣。临床上ARMD分为两种亚型：非渗出型(干性或萎缩型)和渗出型(湿性或新生血管型)。该病的发生是年龄、环境、遗传、吸烟、氧化应激和心血管功能障碍等多种因素相互作用的结果。鉴于RPE细胞在ARMD发病中的重要作用,现以RPE细胞为重点,总结了蓝光、吸烟、氧化应激、脂褐素积累、慢性炎症和蛋白质稳态对干性ARMD发病的作用和可能机制,为认识和预防干性ARMD的发生提供新的帮助。     

蓝光诱导猪视网膜色素上皮细胞复制衰老的实验研究

目的观察蓝光对猪视网膜色素上皮（retinal pigment epithelium,RPE）细胞复制衰老过程中衰老相关-β-半乳糖苷酶（senescence associated-beta-galactosidae,SA-β—Gal）的影响。方法将第3—6代猪RPE细胞置于自制蓝光发光二极管（light emitting diode,LED）光源下,波长450～500nm,1h／d;细胞表面水平光照强度分别为（500±100）lux、（1000±200）lux、（2000±500）lux,光照时细胞水平面的温度变化为36．5—37．5℃;对照组用黑纸完全包裹培养瓶。将各组细胞消化后接种于24孔板和96孔板培养24h,进行SA-β-Gal活性的检测和MTT法检测细胞增殖情况。结果随光照强度和传代次数增加,细胞内出现蓝色颗粒的阳性细胞数目逐渐增多,SA-β-Gal活性增高,除高强度与中强度光照组、第4代和第5代之间相比差别没有统计学意义（P〉0．05）外,其余每两组之间的差异均具有统计学意义（P〈0．05）;通过MTT法检测,细胞的增殖能力随光照强度和传代次数增加而降低,除中强度与低强度光照组相比差别没有统计学意义（P〉0．05）外,其余每两组之间的差异均具有统计学意义（P〈0．05）。结论蓝光可以诱导体外培养猪RPE细胞复制衰老,并且光照强度增加可以促进细胞复制衰老。     

蓝光对视觉功能的利与弊

蓝光在夜视力及调节昼夜节律中起着重要作用,但蓝光可引起视杆细胞及视网膜色素上皮细胞光损伤,与老年性黄斑变性的发病有关。植入滤过蓝光人工晶状体后能否减少老年性黄斑变性的发病率尚有待大样本的研究证实。对已存在老年性黄斑变性及糖尿病视网膜病变的患者植入滤过蓝光人工晶状体是否会加重夜视力的损伤也有待于进一步研究。     

Visual function with blue light filter IOLs

BACKGROUND: Recently, intraocular lenses (IOLs) with a blue light filter have been introduced to protect the retina from age-related macular degeneration (AMD) after cataract extraction. A reduction of longitudinal chromatic aberration by filtering blue light may enhance patient's visual function. In this study we compared subjective and objective parameters of visual function following implantation of blue light filter (yellow) IOLs and IOLs of the same design without filter. PATIENTS AND METHODS: 21 patients (21 eyes) underwent implantation of an IOL with a blue light filter (AF-1 UY, Hoya, Japan), 22 patients (22 eyes) received an IOL without blue light filter (AF-1 UV, Hoya, Japan). Patients were examined three months postoperatively for uncorrected and best corrected spectacle visual acuity, mesopic and photopic contrast sensitivity, colour vision and subjective quality of vision by a standard questionnaire. RESULTS: Eyes with blue light filter IOLs did not show any significant difference in any parameter analysed when compared to eyes without the blue light filter IOL. Subjective quality of vision was considered to be high by all patients and no significant difference was observed between the two IOL groups. CONCLUSION: The visual function of patients with blue filter IOLs is not significantly different to those without blue light filter IOLs. Since blue light filter IOLs did not show any functional disadvantage, but potentially protect the macula from AMD, blue light filter IOLs may be considered as a reasonable alternative to traditional IOLs, especially in eyes with a high risk for the development of macular degeneration.     

评价SMILE术后视觉质量与光学调制传递函数的关系

目的:探讨飞秒激光小切口角膜基质透镜取出术(SMILE)术后光学调制度传递函数(MTF)特点,并探究术后裸眼视力(UCVA)、对比敏感度功能(CSF)与MTF的关系。方法:横断面选取2015-06/11在天津市眼科医院行SMILE手术矫正近视患者34例68眼,术后眼部情况稳定3mo以上且术后残余屈光度均小于±0.50D。在明视觉下,用国际标准视力表测量UCVA,用CSV-1000E测量CSF。用WaveScan测量全眼的波前像差,经Matlab编程,将像差进行公式转换成MTF,取3、6、12、18c/d四频区结果进行统计。结果:在3、6、12、18c/d频区,CSF值分别为:63.19±3.18、110.25±5.22、57.65±3.76、16.15±1.04;MTF值分别为:0.80±0.02、0.56±0.03、0.30±0.02、0.19±0.02。在6、12、18c/d频区,UCVA与CSF具有相关性(r=0.548、0.337、0.324,P<0.01、=0.005、0.007);而在18c/d频区,CSF与MTF具有相关性(r=0.241,P=0.048)。结论:SMILE手术矫正后光学质量(MTF)的变化规律不同于视觉质量的变化规律,不同于视力和对比敏感度,虽然屈光系统发生像差等变化,但最终手术对全眼CSF无影响,说明视神经大脑通路对视觉质量具有补偿作用。计算MTF对评价手术后光学质量的判断具有一定的理论和临床应用价值。     

The relationship between serum trace element changes and visual function in heavy smokers

PURPOSE: The aim of this prospective study was to evaluate serum manganese (Mn), zinc (Zn) and copper (Cu) levels and visual functions including visual acuity, colour vision, pattern visual evoked potentials (PVEPs), and contrast sensitivity in heavy smokers and to compare these with the equivalent levels and functions in non-smokers. METHODS: Data were recorded in 24 healthy, chronic and heavy cigarette smokers and 16 healthy, non-smoking control subjects. Serum Zn, Cu and Mn concentrations in all subjects were measured by atomic absorption spectrophotometry. RESULTS: Both study and control subjects had normal visual acuity and colour vision. Pattern visual evoked potentials were normal in all study and control subjects. Contrast sensitivity was significantly reduced in heavy smokers compared to non-smokers (p < 0.023), despite the fact that central vision and PVEP responses were not affected. Mean serum Mn and Zn levels were significantly lower in smokers than in non-smokers (p < 0.0001 and p < 0.005, respectively). CONCLUSIONS: Reduced contrast sensitivity values associated with low levels of serum Mn and Zn, which function as cofactors of superoxide dismutase in erythrocyte and other nucleated cells, suggest a possible role of trace elements in smoking-induced early retinal toxicity.     

Evaluation of the relationship between quality of vision and the visual function index in Japanese glaucoma patients

Background  

We compared two types of visual field index including mean deviation (MD) and the visual field index (VFI) for assessing the relationship between quality of life (QOL) and the loss of visual field in open-angle glaucoma patients.     

Cobalt blue light unit filter - A smartphone attachment for blue light photography

Purpose:The aim of this study was to carry out blue light photography of fluorescein-stained corneas using a novel smartphone attachment.Methods:A smartphone attachment known as the cobalt blue light unit (C-BLU) was developed. It can filter out all wavelengths of light except the blue light emerging from the flashlight of a smartphone. A pilot study was carried out wherein the images captured with the C-BLU system were compared with slit-lamp photographs of the same patients. This setup was then used to photo document fluorescein-stained corneas in various clinical settings assembled at point-of-care.Results:Many pathologies of the fluorescein-stained cornea were captured using the C-BLU filter. It was used effectively in various settings (remote eye camps, intensive care units (ICU), pediatric group, corneal trauma triaging, etc.). C-BLU was assembled and used by optometrists and ophthalmology residents. The images captured were used for documenting, assisting in the treatment, and also for telecommunication of the patients’ findings.Conclusion:C-BLU is a low-cost pocket-size filter which is easy to use with a modern smartphone without any technical expertise needed to obtain a clear image of fluorescein-stained pathological corneas.