Structural measurements and vessel density of spectraldomain optic coherence tomography in early,moderate,and severe primary angle-closure glaucoma

AIM:To compare the macular ganglion cell-inner plexiform layer(GCIPL)thickness,retinal nerve fiber layer(RNFL)thickness,optic nerve head(ONH)parameters,and retinal vessel density(VD)measured by spectral-domain optical coherence tomography(SD-OCT)and analyze the correlations between them in the early,moderate,severe primary angle-closure glaucoma(PACG)and normal eyes.METHODS:Totally 70 PACG eyes and 20 normal eyes were recruited for this retrospective analysis.PACG eyes were further separated into early,moderate,or severe PACG eyes using the Enhanced Glaucoma Staging System(GSS2).The GCIPL thickness,RNFL thickness,ONH parameters,and retinal VD were measured by SD-OCT,differences among the groups and correlations within the same group were calculated.RESULTS:The inferior and superotemporal sectors of the GCIPL thickness,rim area of ONH,average and inferior sector of the retinal VD were significantly reduced(all P<0.05)in the early PACG eyes compared to the normal and the optic disc area,cup to disc ratio(C/D),and cup volume were significantly higher(all P<0.05);but the RNFL was not significant changes in early and moderate PACG.In severe group,the GCIPL and RNFL thickness were obvious thinning with retinal VD were decreasing as well as C/D and cup volume increasing than other three groups(all P<0.01).In the early PACG subgroup,there were significant positive correlations between retinal VD and GCIPL thickness(except superonasal and inferonasal sectors,r=0.573 to 0.641,all P<0.05),superior sectors of RNFL thickness(r=0.055,P=0.049).More obvious significant positive correlations were existed in moderate PACG eyes between retinal VD and superior sectors of RNFL thickness(r=0.650,P=0.022),and temporal sectors of RNFL thickness(r=0.740,P=0.006).In the severe PACG eyes,neither GCIPL nor RNFL thickness was associated with retinal VD.CONCLUSION:The ONH damage and retinal VD loss appears earlier than RNFL thickness loss in PACG eyes.As the PACG disease progressed from the early to the moderate stage,the correlations between the retinal VD and RNFL thickness increases.

Intraocular pressure modifications in patients with acute central/hemicentral retinal vein occlusions

Intraocular pressure(IOP)modifications in patients with acute central/hemicentral retinal vein occlusions(RVOs)consist in IOP reductions and increases.The IOP reduction is due to a transitional hyposecretory phase of the aqueous humor,that increases gradually until 3 mo after the venous occlusion onset,and then finally disappears after month 4 th.The IOP increases lead to the ocular hypertension and glaucoma.The possible pathogenetic correlations between ocular hypertension/glaucoma and acute central/hemicentral RVOs have been classified into three groups:1)the venous occlusion precedes the ocular hypertension/glaucoma causing neovascular glaucoma and secondary angle-closure glaucoma without rubeosis;2)the ocular hypertension and the glaucoma precede the venous occlusion and favor its appearance(ocular hypertension,primary angle-closure,primary angle-closure glaucoma,and open angle glaucomas);and 3)the venous occlusion and the ocular hypertension/glaucoma are mostly age dependent appearances due to common vascular and collagen alterations,lacking a causal connection between the 2 conditions.

高度近视合并原发性开角型青光眼特征分析

目的探讨高度近视合并原发性开角型青光眼(primary openangle glaucoma,POAG)的视乳头形态、视网膜神经纤维层(RNFL)缺损及其与视野改变的特点之间的关系。方法采用回顾性对照研究方法,将43例患者73眼分为4组:A组为高度近视合并POAG组;B组为单纯高度近视非POAG组;C组为非高度近视POAG组;D组为正常组。分别采集3类指标:1视乳头杯盘横径比、垂直径比、盘沿/视盘面积比值;2视神经纤维层厚度数值;3视野图平均光敏感度及平均视野缺损MD值。最后通过SPSS 19.0软件统计分析各组患者3类指标的变化特点及其之间的关系。结果 A组盘沿面积明显小于B组或C组,A组杯盘横径比值大于杯盘纵径比值,和C组眼底损害相一致,而B组杯盘纵径比值与杯盘横径比值差异无统计学意义(P>0.05);A组患者平均光敏感度、MD值与其他3组相比,差异均具有统计学意义(P均<0.05)。A组RNFL厚度明显小于B组或C组,此3组较正常组RNFL均变薄。结论单纯的高度近视或POAG患者眼底形态及视野检查有相似的改变,但不完全相同,且RNFL厚度与视野对应部位的缺损相关,而合并高度近视的POAG患者这种变化较其他两组更显著。

硫化氢对眼科疾病潜在治疗作用的研究进展

硫化氢(H_2S)作为一个新的内源性气体信号分子,参与多种生理与病理效应,如对抗缺血性损伤,减轻氧化应激损伤,抑制细胞凋亡和减轻炎症反应等。目前已从多方面证实了H_2S的治疗潜能,无论是内源性H_2S生成还是外源性供给H_2S,都参与了一系列细胞保护作用。本文综述了H_2S在一些眼科疾病的病理生理过程中的保护机制。

青光眼视神经损伤机制的研究进展

青光眼是目前继白内障后全球第2位致盲性眼病,总人群发病率为1%,严重威胁着人类的视觉健康。关于青光眼视神经损伤的发病机制,近年来各国学者在该领域做了大量的研究,许多学说都证实其最终的共同通路是视网膜神经节细胞的凋亡,然而每一种学说都不能完全解释青光眼视神经损害的具体机制。到目前为止,其确切机制尚未阐明,因此,有必要进行更深入的研究,在合理的理论框架下,探索特异性阻断视网膜神经节细胞凋亡的新方法,从而更有效地保护视功能。

超声乳化联合人工晶体植入术治疗眼底损害的闭角型青光眼合并白内障效果观察

目的观察超声乳化联合人工晶体植入术治疗眼底损害的闭角型青光眼合并白内障的临床疗效。方法 30例(32眼)眼底损害的闭角型青光眼合并白内障患者,使用白内障超声乳化联合人工晶体植入术治疗。观察患者术前、术后的眼压、视力、前房深度、眼底及视野等。结果术后1周所有患者的眼压、视力、眼房深度均得到了明显的改善,差异有统计学意义(P<0.05)。术后6个月有23眼(71.88%)眼压升高需加用药物控制眼压,其中6眼(26.09%)行小梁切除术。结论超声乳化联合人工晶体植入术治疗眼底改变的闭角型青光眼强调密切随访或改用联合手术。

氧化损伤在青光眼发病中的作用

青光眼是一种多因素诱导的视神经退行性病变，其中氧化应激损伤在复杂的青光眼发病机制中的起着重要作用。青光眼的氧化损伤机制可能对眼部的某些组织细胞产生损伤作用，促使细胞内抗氧化物酶作用下降、抗氧化作用相关蛋白增加，最终导致蛋白沉积、细胞死亡。氧化损伤可以导致小梁网细胞线粒体骨架改变，最终使小梁网发生退行性病理改变。氧化损伤还可促使视网膜神经节细胞内抗氧化作用相关蛋白增加、线粒体内源性凋亡，最终导致视网膜神经节细胞功能丧失。（国际眼科纵览，2013，37：59—62）

脑红蛋白在眼科的研究现状

脑红蛋白（neuroglobin，NGB）是继血红蛋白和肌红蛋白之后发现的第三类神经系统特异的携氧球蛋白，与氧有很高的亲和力，具有重要的神经保护功能。近来发现NGB在视网膜内的含量是大脑的100倍，高表达的NGB对眼部组织的缺血缺氧、氧化应激损伤有一定的保护作用，在眼科疾病的发生发展中亦具有重要的研究价值。本文主要针对NGB的眼内分布、神经保护机制及其在视网膜光化学损伤、糖尿病视网膜病变、青光眼等眼科疾病中发挥的作用进行综述。