摘要目的 探讨甘油醛对巩膜生物力学特征的影响及其对实验性近视眼的抑制作用.方法 实验研究.选取50只3周龄三色豚鼠,按随机数字表法分成5个组,每组10只.右眼为实验眼,左眼为对照眼.A组:右眼遮盖7d;B、C、D组:右眼遮盖21 d后分别给予0.9％生理盐水、0.05 mol/L甘油醛、0.5 mol/L甘油醛第1、8、15天Tenon囊下球后注射;E组:正常对照组.在每组中采用随机数字表法选取7只豚鼠行实验前及剥夺后7、14、21d的眼轴、屈光度及生物力学参数极限应力、极限应变、6％弹性模量的测量,其余3只豚鼠行组织学检查.实验眼和对侧眼之间数据的比较采用配对t检验,对眼轴与屈光度进行二元变量相关分析.结果 形觉剥夺后,A、B、C组实验眼玻璃体腔长度分别为(2.991±0.078)、(2.961±0.038)、(2.936±0.021) mm,眼轴长度分别为(7.263±0.133)、(7.732±0.099)、(7.665±0.055) mm,屈光度数分别(-2.214±2.881)、(-4.525±2.415)、(-1.607±0.866)D,与对侧眼相比,差异有统计学意义(t玻璃体腔=3,234,4.758,7.608;P玻璃体腔=0.018,0.002,0.001;t眼轴 =3.198,4.758,7.608;P眼轴=0.019,0.002,0.000;t屈光=-7.120,-4.020,-6.334;P屈光=0.000,0.005,0.001).D组、E组玻璃体腔长度、眼轴长度与对侧眼相比,差异无统计学意义(t玻璃体腔=0.542,-0.646;P玻璃体腔=0.607,0.539;t眼轴=0.542,-0.646;P眼轴=0.607,0.539).D组实验眼屈光度为(-3.921±0.874)D与对侧眼(-3.321±1.205)D相比差异有统计学意义(t屈光=-3.154,P屈光=0.020).在实验第21天结束时,B、C、D、E组实验眼的屈光度变化值总体差异有统计学意义(F=61.249,P=0.000),B、C、D组的屈光度变化值分别为(8.800±0.616)、(7.236±2.198)、(6.271±1.112)D,较正常对照组(0.934±0.158)D大,差异有统计学意义(PB=0.000,PC=0.000,PD=0.000).试验结束时,B组实验眼的极限应力和6％弹性模量分别为(7.988±3.677) MPa(P =0.002)和(19.938±4.871)MPa(P =0.001),较对侧眼分别降低了34.21％和34.38％,极限应变实验眼为(28.6±3.6)％(P =0.034),较对侧眼增加了19.17％.甘油醛交联后,C组实验眼的极限应力和6％弹性模量分别为(9.244±0.806) MPa(P=0.001)和(26.180±4.388) MPa(P =0.031),较对侧眼分别降低了23.13％和13.34％,极限应变实验眼为(26.2±1.0)％(P=0.016),较对侧眼增加了12.93％;D组实验眼的极限应力为(12.476±2.507)MPa(P=0.580),较对侧眼降低了5.50％,6％弹性模量为(30.446±3.410) MPa(P =0.314),较对侧眼增加了6.53％,极限应变为(23.8±1.8)％(P=0.253),较对侧眼降低了4.42％.不同浓度甘油醛交联与对照组实验眼的应力-应变曲线有明显的梯度变化.组织学检查:甘油醛交联后出现了巩膜组织的厚度变薄,细胞密度增加.无炎性细胞浸润.MMP-2在浅层巩膜、脉络膜实质层以及视网膜外丛状层的阳性表达明显降低.结论 甘油醛是一种安全有效的交联剂,能够显著增强巩膜的生物力学强度.采用甘油醛交联的方法能够有效控制形觉剥夺性近视眼(FDM)动物模型眼近视眼的发展.

abstractsObjective The purpose of this study is to observe the effects of glyceraldehyde crosslinking on sclera biomechanical strength and experimental myopia.Methods 50 three weeks aged guinea pigs were randomly divided into 5 groups:A,B,C,D,E.Each group had 10 guinea pigs.The right eye was set as the experimental eye,the left eye was used as control.Group A:7 days mask; Group B:21 days mask,plus physiological saline retrobulbar injection at mask day 1,8,15 ; Group C:21 days mask,plus 0.05 mol/L glyceraldehyde retrobulbar injection at mask day 1,8,15; Group D:21 days mask,plus 0.5 mol/L glyceraldehyde retrobulbar injection at mask day 1,8,15; Group E:normal control group.Several parameters of 7 guinea pigs of each group were measured before and after deprivation (mask day 7,14,21),including ocular axial length,refractive error,ultimate stress (σmax) (MPa),ultimate strain (εmax) (％) and 6％ elastic modulus(MPa).The effects of glyceraldehyde on adjacent tissues of the rest 3 guinea pigs were detected by histopathological and immunohistochemical studies.Differences between experiment eyes and contralateral,eyes were compared with paired t test and correlative analysis.Results The experimental eyes appeared the increase of the the vitreous cavity length,the axial length and myopia after deprivation.In group A,group B and group C,the differences of the length of the vitreous cavity (group A (2.991 ± 0.078) mm,group B (2.961 ± 0.038) mm and group C (2.936 ± 0.021) mm),the axial length (group A(7.263 ± 0.133) mm,group B (7.732 ± 0.099)mm and group C (7.665 ± 0.055)mm) and refractive error (group A (-2.214 ± 2.881) D,group B (-4.525 ± 2.415) D and group C (-1.607 ± 0.866) D) between the experimental eye and the fellow eye was statistically significant (tvitreous cavity =3.234,4.758,7.608 ; Pvitreous cavity =0.018,0.002,0.001 ; taxial =3.198,,4.758,7.608 ; Paxial =0.019,0.002,0.000; trefraction =-7.120,-4.020,-6.334; Prefraction =0.000,0.005,0.001).In group D and group E,there is no difference between deprived eye and control eye about the length of the vitreous chamber as well as axial length (tvitreous =0.542,-0.646 ; Pvitreous cavity =0.607,0.539 ; taxial =0.542,-0.646 ; Paxial =0.607,0.539).The experimental eye ((-3.921 ±0.874) D)and the fellow eye ((-3.321 ± 1.205)D)of group D,the difference of diopter was statistically significant (trefraction =-3.154,Prefraction =0.020).At the end of the experiment,the change of diopter of experimental eye of group B,C,D,E was significantly different (F =61.249,P =0.000).The difference of diopter change between group B ((8.800 ±0.616)D),group C ((7.236 ± 2.198) D),group D ((6.271 ± 1.112) D) and the normal control group ((0.934 ± 0.158) D) was statistically significant (PB =0.000,PC =0.000,PD =0.000).At the end of the experiment,the ultimate stress and 6％ elastic modulus of group B experimental eye was (7.988 ± 3.677)M Pa (P =0.002) and (19.938 ± 4.871) M Pa (P =0.001),decreased 10.06％ and 34.17 ％ respectively.On the other hand the ultimate strain was (28.6 ± 3.6)％ (P =0.034),increased 19.17％.After the crosslinking treatment,the ultimate stress and 6％ elastic modulus of group C experimental eye was (9.244 ±0.806) MPa(P =0.001) and (26.180 ± 4.388) MPa(P =0.031),decreased 23.13％ and 13.34％,the ultimate strain was (26.2 ± 1.0)％ (P =0.016),increased 12.93％ separately.The ultimate stress of group D experimental eye was (12.476 ± 2.507) MPa(P =0.580),decreased 5.50％,6％ elastic modulus was (30.446 ± 3.410) MPa(P =0.314),increased 6.53％,ultimate strain was (23.8 ± 1.8) ％ (P =0.253),decreased 4.42％ respectively.Ultrastructure examination showed that,decreased scleral thickness with fibers lined up in order,without inflammatory cells Infiltration.Expressions of matrix metalloproeinases-2 (MMP-2) mainly decrease in the episcleral tissue.The stroma of choroid,and the outer plexiform layer.Conclusions Glyceraldehyde is a safe and effective cross-linking agent that could significantly enhance the sclera biomechanical strength.Glyceraldehyde cross-linking method could effectively control the development of myopia in animal model.