Glycol Methacrylate Sections of the Crystalline Lens

Sections of the crystalline lens are difficult to prepare because of the hardness of the fixed lens. After paraffin procedures the lens shatters and cracks when cut because the reagents and high temperatures used for infiltration further harden it. Plastic has been successfully used as an embedding medium for other difficult tissues. It allows prolonged infiltration times at room temperature, and provides a firm matrix for tissues containing areas of varying density. However, standard procedures for embedding tissue in plastic do not allow for complete infiltration of the crystalline lens. The purpose of this report is to describe a modification of the glycol methacrylate embedding technique which ensures complete infiltration of the lens. The following protocol was found to produce consistently good 1-5 μm sections of lenses from 10-2O-day-old rats.     

超声乳化人工晶状体植入术治疗高度近视合并白内障的效果

目的:探讨超声乳化人工晶状体植入术在高度近视合并白内障中的应用及对中央角膜厚度(CCT)、角膜内皮细胞计数(CEC)、图像视觉诱发电位(P-VEP)与黄斑光学相干断层成象(OCT)的影响。方法:选择2014年1月至2016年6月我院接诊的96例高度近视合并白内障患者,通过随机数表法分为观察组(n=48)和对照组(n=48)。对照组行白内障囊外摘出人工晶状体植入术,观察组行超声乳化人工晶状体植入术。手术1个月后,比较两组CCT、CEC、P-VEP、黄斑OCT、最佳矫正视力以及并发症的发生情况。结果:手术后,观察组CCT、CEC均明显高于对照组(P0.05)。P-VEP检测结果显示观察组P100波振幅明显高于对照组,P100波潜时显著低于对照组(P0.05)。黄斑OCT结果显示观察组黄斑中心凹厚度明显低于对照组(P0.05);观察组最佳矫正视力明显高于对照组(P0.05);观察组并发症的总发生率明显低于对照组(P0.05)。结论:应用超声乳化人工晶状体植入术治疗高度近视合并白内障患者的效果显著,可有效减轻对角膜内皮的损伤,促进视力恢复,提高视觉质量。     

ICL植入术矫正高度近视的短期临床观察

目的:观察后房型有晶体眼人工晶体(implantable contact lens,ICL)植入术矫正高度近视术后早期的有效性和安全性。方法:选择于我院行ICL植入术的高度近视患者18例(36眼),于术前及术后1周、1个月、3个月随访记录其裸眼视力(uncorrected visual acuity,UCVA),最佳矫正视力(best corrected visual acuity,BCVA),等效球镜(spherical equivalent,SE),前房深度(anterior chamber depth,ACD),眼内压(intraocular pressure,IOP),角膜内皮细胞密度(endothelial cell density,ECD)的变化。结果:所有患者术后3个月裸眼视力和有效球镜度均较术前显著提高(P0.05),前房深度较术前变浅(P0.05),眼内压与术前对比无明显差异(P0.05),角膜内皮细胞密度较术前显著减少(P0.05)。结论:ICL植入手术矫正高度近视的短期临床疗效和安全性均较好。     

Electrical Properties of Structural Components of the Crystalline Lens

The electrical properties of the crystalline lens of the frog eye are measured with stochastic currents applied with a microelectrode near the center of the preparation and potential recorded just under the surface. The stochastic signals are decomposed by Fourier analysis into sinusoidal components, and the impedance is determined from the ratio of mean cross power to input power. The data are fit by an electrical model that includes two paths for current flow: one through the cytoplasm, gap junctions, and outer membrane; the other through inner membranes and the extracellular space between lens fibers. The electrical properties of the structures of the lens which appear as circuit components in the model are determined by the fit to the data. The resistivity of the extracellular space within the lens is comparable to the resistivity of Ringer. The outer membrane has a normal resistance of 5 kohm · cm² but large capacitance of 10 μF/cm², probably because it represents the properties of several layers of fibers. The inner membranes have properties reminiscent of artificial lipid bilayers: they have high membrane resistance, 2.2 megohm · cm², and low specific capacitance, 0.8 μF/cm². There is so much membrane within the lens, however, that the sum of the current flow across all the inner membranes is comparable to that across the outer surface.     

Defects of the Lamina Cribrosa in High Myopia and Glaucoma

Purpose

We evaluated the prevalence and characteristics of the defects of the lamina cribrosa (LC) in high myopia and glaucoma, and compared them with control eyes using swept-source optical coherence tomography (SS-OCT).

Methods

One hundred fifty-nine eyes of 108 participants were divided into four subgroups; high myopia with glaucoma (MG, 67 eyes of 46 subjects), glaucoma without high myopia (G, 22 eyes of 13 subjects), high myopia without glaucoma (M, 35 eyes of 29 subjects), and a control group with neither glaucoma nor high myopia (C, 35 eyes of 20 subjects). The LC defects were identified and located using a standardized protocol in serial horizontal OCT scans. The prevalence rates of the defects were compared among the groups. Demographic and ocular factors were compared between eyes with and without defects.

Results

LC defects were observed in one eye (0.03%) in the C group, 8 eyes (22.9%) in the M group, 11 eyes (50%) in the G group, and 28 eyes (41.8%) in the MG group. The prevalence rates of the defects differed significantly among the groups (P = 0.0009). Most eyes with defects in the G and MG groups (79.5%) had damage in the corresponding visual hemifields. Other factors such as visual acuity, intraocular pressure, axial length, refractive error, disc ovality, or parapapillary atrophy area did not differ significantly between eyes with and without LC defects.

Conclusions

High myopia and glaucoma significantly increased the risk of LC damage. The LC damage in non-glaucomatous highly myopic eyes may at least partly explain the increased risk of developing glaucoma in myopic eyes.     

III型神经中丝蛋白基因与中国高度近视人群相关性的研究

为了检测peripherin基因（PRPH）的突变与高度近视的病因有无相关关系,采用PCR-SSCP检测180例中国人高度近视先证者及60例正常人中PRPH基因所有外显子有无突变;对有突变的外显子区域进行克隆测序。结果表明,分析180例高度近视先证者PRPH基因编码区9个外显子及其邻近内含子,分别发现有下列核苷酸改变：密码子21TTC→TTT(Phe21Phe、4/180),nt2138C→G（IVS3、1/180）,密码子277GCC→ACC（Ala277Thr、8/180）,密码子237CCA→TCA（Arg237stop、1/180）,密码子292GCG→GCA(Ala292Ala,1/180),密码子361CUG→CUC（Leu361Leu,12/180）,密码子369AAA→AAG（Lys369Lys,12/180）,nt3331G→C（IVS7、3/180）,其中GCC277ACC为错义突变（Ala277Thr）;CCA237TCA为无义突变（Arg237stop）;密码子361CUG→CUC,密码子369AAA→AAG属于同义突变并且相连锁。Ala277Thr突变尚存在于正常人群中（1/60）,亦存在于患者正常亲属中;Arg237stop仅见于一个常染色体隐性遗传家系的患者中,为杂合性突变。分析180例高度近视先证者PRPH基因,未发现致病突变,可排除PRPH基因与高度近视病因的相关性。在中国人群中PRPH基因有多种变异。 Variation of the Peripherin Gene in Chinese with or Without High Myopia LI Jiang1,ZHANG Qing-jiong1,FU Rong2,XIAO Xue-shan1,LI Jia-zhang3,ZHANG Feng-sheng4, LI Shi-qiang1,LI Wei5,LI Tuo3,JIA Xiao-yun1,GUO Li1,GUO Xiang-ming 1.Zhongshan Ophthalmic Center,Sun Yat-sen University,Guangzhou 510060,China; 2.Shenzhen Municipal People's Hospital,Shenzhen 518000,China; 3.Department of Opthalmolgy,The people's Hospital of Enshi Autonomous Prefecture,Enshi 445000,Hubei,China; 4.Chaoju Eye Hospital,Baotou,Inner Mongolia 014000,China; 5.Shenzhen 2nd People's Hopital,Shenzhen 518000,China Abstract:To analyze the relationship of the peripherin gene(PRPH,OMIM17071) mutations with high myopia,genomic DNA was collected from 180 probands with high myopia (≤-6.0 dipoters) and 60 unrelated persons without high myopia.The coding sequences of PRPH gene in 240 subjects were analyzed using exon-by-exon PCR-heteroduplex-SSCP analysis and sequencing.Variations at codon21TTC→TTT(Phe21Phe、4/180),nt2138C→G（IVS3、1/180）,codon277 GCC→ACC（Ala277Thr、8/180）,codon237 CCA→TCA （Arg237stop、1/180）,codon292CCG→CCA (Ala292Ala,1/180),codon361CUG→CUC（Leu361Leu,12/180）,codon369 AAA→AAG（Lys369Lys,12/180）,nt3331G→C（IVS7、3/180）were detected in a number of probands as indicated in the blanket.Of the 8 variations one( codon 277,G→A,Ala277Thr) is a missense mutation identified in 8 of the 180patients and one of 60 controls;The mutation of codon361 and codon 369were synonymous one and linkage each other;Another one(codon237,CCA→TCA,Arg237stop) is a heterozygous nonsense mutation identified in one patient with autosomal recessive inheritance mode population but not in the 60 normal controls.The others were synonymous mutations.Eight nucleotide variations were found in the PRPH gene.We found no evidence that mutations in the PRPH gene are responsible for the high myopia in Chinese. Key words：high myopia; peripherin gene; PCR-SSCP     

框架眼镜联合角膜塑形镜矫正青少年高度近视的临床疗效及对角膜内皮细胞和泪膜的影响

目的:探讨框架眼镜联合角膜塑形镜矫正青少年高度近视的临床疗效及对角膜内皮细胞和泪膜的影响.方法:选取2018年1月～2019年3月期间我院收治的青少年高度近视患者98例(181眼),根据信封抽签法分为对照组49例92眼(框架眼镜配戴治疗)和观察组49例89眼(对照组基础上联合角膜塑形镜治疗).对比两组裸眼视力、屈光度、...     

ZFP161基因与中国高度近视人群的相关性研究

为了探讨ZFP161基因与高度近视的相关性,从而寻找高度近视的致病基因,以来自不同地区和家系的中国单纯性高度近视先证者204例和排除高度近视及相关疾病的正常人116例为材料,采用PCR-SSCP法检测病例组及正常人群外周血白细胞基因组DNA中ZFP161基因2个外显子是否存在基因突变,对存在突变的外显子区域经克隆测序后确定变异性质,结合对照组及家系分析确定ZFP161基因突变与高度近视的相关性。结果表明：1.ZFP161基因内含子1第58号碱基前存在AT序列插入突变,即IVS1 58～59突变(1/204),该突变仅存在于高度近视先证者中;2.ZFP161基因外显子2的第168号碱基由C颠换为A,即Ala56Ala突变(Codon56 GCC→GCA, Ala56Ala)(5/204),该突变存在于正常人群中（3/116）,亦存在于患者的正常亲属中;结合正常对照和家系分析,初步排除ZFP161基因与中国单纯性高度近视之间的相关性。Abstract: To investigate the association between variations of ZFP161 gene and high myopia, A total of 204 probands with simple high myopia(≤-6.0 dipoters) were collected while 116 normal persons from different families without high myopia or related disease were used as controls. Genomic DNA was prepared from the peripheral leucocytes. The coding sequences of ZFP161 gene in 320 subjects were analyzed by using exon-by-exon PCR-heteroduplex-SSCP analysis. Identification of the Variations by cloning and sequencing, combinated with controls and family analysis, was used to disclose the correlation between ZFP161 gene and high myopia. A mutation of ZFP161 gene was identified as an insertion of AT before the 58th nucleotide of intron 1 (IVS1 58-59)(1/204) and a variation of ZFP161 gene was identified as a heterozygous C to A of the 168th nucleotide in exon 2 (Codon56, GCC→GCA, Ala56Ala). Ala56Ala is a non-sense mutation identified in 5 of the 204 patients and 3 of 116 controls. No evidence shows that these variations are responsible for high myopia.     

高度近视准分子激光原位角膜磨镶术后屈光回退的相关分析

目的:探讨高度近视准发子激光原位角膜镶术(laser insitu keratomileusis,LASIK)手术后屈光回退与术前各项检查结果间的相关性。方法:将135例(241只眼)近视患者按屈光度数分为A组126只眼(-6.00 D~-9.00 D)和B组115只眼(≥-9.00 D)。记录术前的屈光度数、眼压和角膜厚度,依据预期校正屈光度数计算理论残余角膜厚度,行LASIK手术后记录术后视力、屈光度数,进行统计学分析。术后平均随访时间19.14个月。结果:A组中正常术眼108只眼(85.7%),回退术眼18只眼(14.3%);B组中正常术眼74只眼(64.3%),回退术眼41只眼(35.7%);两组比较差异有非常显著意义(P<0.01)。术后平均视力A组为1.17±0.20,B组为0.99±0.28,两组比较差异有非常显著意义(P<0.01)。两组术后的平均屈光度数比较,差异有非常显著意义(P<0.01)。平均理论残余角膜厚度A组为(452.53±28.47)μm,B组为(439.61±30.11)μm,两者比较,差异有非常显著意义(P<0.01)。屈光回退度数与术前近视屈光度数显著正相关(r=0.35,P<0.001),与理论残余角膜厚度显著负相关(r=0.13,P=0.04),与术前眼压及术前角膜厚度无相关性(r=-0.48,P=0.46;r=-0.39,P=0.55)。结论:LASIK手术术前屈光度数越大,术前计算的理论残余角膜厚度越小,术后越易出现回退。对于-6.0 D~-9.00 D的高度近视患者,LASIK手术的预测性和术后稳定性相对较好;对于≥-9.00 D的超高度近视患者,应结合手术技术和术前计算的理论残余角膜厚度慎重选择进行手术。