【作者】 田姣；

【导师】 唐罗生；

【作者基本信息】 中南大学 ， 临床医学， 2013， 博士

【摘要】 研究背景随着医学水平的进步和人们生活质量的提高,对眼后节疾病的研究、诊断和治疗也达到了一个新的高度。如老年性黄斑变性、色素层炎、高度近视、糖尿病视网膜病变、中心性渗出性脉络膜视网膜病变和视网膜血管阻塞等,采用积极的局部药物治疗是提高预后视力的保障,而玻璃体腔药物注射也日渐成为眼科临床上最常用的方法之一。玻璃体腔药物注射能使药物直接作用于眼后节,避免了全身用药带来的不良反应,同时也避免了血眼屏障对药物传递的影响。因此在治疗眼后节疾病时能使更多剂量的药物到达病变部位,从而取得良好的疗效。但是玻璃体腔药物注射同时也存在一些缺陷,如进入眼球带来的损伤,造成玻璃体积血、视网膜脱离、并发性白内障、眼内炎等并发症。针对这个缺陷,有各种非穿透眼球壁的方法的研究,如球周注射、脉络膜下腔注射、电离子透入疗法等。由于眼后节慢性疾病的病程长和药物迅速的扩散和代谢,常常需要多次重复进行玻璃体腔药物注射。针对这个问题,有各种延长药物作用时间的方法的研究,如巩膜塞、眼内植入物、缓释剂等。另外,由于眼球是一个密闭的容积固定的系统,所以在玻璃体腔药物注射时只能是极小的药物剂量,即使小剂量药物也常常会有眼压的骤然升高、眼内物的返流、注射器的药物残留等情况出现。眼压的骤然升高会影响视乳头和视网膜的血液供应,这种情况可能会给本身具有血管疾病或者是既往有青光眼病史的患者带来进一步的损害,而与眼内压升高相关的眼内物的返流和注射器内药物残留可能导致玻璃体嵌顿和药物剂量不准确。但是,通过临床观察和文献阅读我们发现这种眼压升高通常会在短时间内下降至正常。于是我们设想是否眼球存在着眼压自身调节机制,药物能否通过一小段时间以缓慢的速度进入玻璃体腔而保持眼压平稳?我们也设想是否通过这种方法能够提高药物剂量的准确性和调节药物剂量的大小?因此,本研究中我们设计动物模型观察使用输液泵进行玻璃体腔药物泵入的可行性和优缺点,以拓展眼后节药物传递的方法。目的探索兔眼玻璃体腔药物泵入的方法；比较不同给药方式的差别；观察玻璃体腔药物泵入的药物扩散和药物浓度；研究玻璃体腔药物泵入对视网膜功能和结构的影响。方法1.玻璃体腔药物泵入初步设计：选用胰岛素泵作为输液泵,选用与其配套的连接输液管的27G针头,以0.06%台盼蓝溶液为输入液。新西兰兔24只,分A、B、C、D4组,分别于30分钟内向玻璃体腔泵入50、100、150、200μL台盼蓝,每组6眼。分别于0、5、10、15、20、25、30分钟和出针后监测眼压,并观察穿刺口返流、术中眼球变化和术后1周眼部并发症。2.不同给药方法的比较：根据结果1选择进针4mm30分钟泵入100μL (B组)为参照设计E、F、G组。新西兰兔18只,分3组(即E、F、G组),每组6眼,各组均使用27G针头玻璃体腔内进针6mm。E组玻璃体腔注射100μL台盼蓝；F组：1分钟内向玻璃体腔快速泵入100μL台盼蓝,30分钟后出针；G组：30分钟内向玻璃体腔泵入100μL台盼蓝。监测眼压,观察穿刺口返流、注射器中药物残留、术中眼球变化和术后1周内眼部并发症。3.不同分子量药物不同给药方法眼内药物浓度检测：新西兰兔72只,分6组,每组12只24眼。前3组以0.01%的荧光素钠(分子量为376.28)溶液为输入液,左右眼两两配对为进针4mm30分钟玻璃体腔泵入100μL荧光素钠(4mm SF泵入组)、进针6mm30分钟玻璃体腔泵入100μL荧光素钠(6mm SF泵入组)和进针6mm玻璃体腔注射100μL荧光素钠(SF注射组),分别于第1、3、6、18小时处死动物(每个时间点每组6眼),检测前房液和玻璃体液荧光强度。后3组以1%的异硫氰酸荧光素葡聚糖(分子量为150kDa)溶液为输入液,左右眼两两配对为进针4mm30分钟玻璃体腔泵入100μL异硫氰酸荧光素葡聚糖(4mm FD泵入组)、进针6mm30分钟玻璃体腔泵入100μL异硫氰酸荧光素葡聚糖(6mm FD泵入组)和进针6mm玻璃体腔注射100μL异硫氰酸荧光素葡聚糖(FD注射组),分别于第1、3、9、18天处死动物(每个时间点每组6眼),检测前房液和玻璃体液荧光强度。4.不同给药方法对视网膜功能和结构的影响：12只新西兰兔随机分为2组,每组6只12眼。第1组左眼进针6mm30分钟玻璃体腔泵入100μL平衡盐溶液；右眼进针6mm玻璃体腔注射100μL平衡盐溶液。第2组左眼进针6mm1分钟玻璃体腔快速泵入100pL平衡盐溶液；右眼正常对照眼。分别于第1、4、7天行3次治疗,于治疗前,第1次和第3次治疗30分钟后行视网膜电图检查,于第7天行眼球摘除,行视网膜切片光学显微镜下观察视网膜的组织形态结构。结果1.A、B、C、D组玻璃体腔药物泵入过程中的平均眼压分别是17.65±2.56、25.19±1.76、29.13±4.38和39.77±8.54mmHg,单个时间点的最高眼压分别是19.44±4.71、26.89±2.54、32.78±2.92和48.78±4.53mmHg。4组均观察到前房有台盼蓝出现,C组的部分兔眼和D组的全部兔眼可以观察到随着眼压的升高有轻到中度的角膜水肿。2.E组玻璃体腔药物注射后的眼压是46.06±7.12mmHg,注射器内药物残留约10到40μL。F组玻璃体腔药物快速泵入后的眼压均大于60mmHg,但30分钟后眼压均小于20mmHg。G组在药物泵入时的平均眼压为25.27±1.85mmHg,但有2眼晶状体损伤。3.所有30分钟玻璃体腔泵入100μL药物的96只眼的平均眼压为25.11±3.94mmHg。4mm SF泵入组的前房液荧光强度在第1、3、6小时比6mm SF泵入组和SF注射组高,差异有显著性(p<0.05)；4mm FD泵入组的前房液荧光强度在第1天比6mm FD泵入组和FD注射组高,差异有显著性(p<0.05),表明进针较浅时药物容易从前房流失。6mm SF组玻璃体液荧光强度在第1、3、18小时比4mm SF泵入组高,差别有显著性(p<0.05)；6mm FD泵入组玻璃体液荧光强度在第9、18天比4mm FD泵入组高,差异有显著性(p<0.05),表明进针的深度与玻璃体腔药物浓度相关。6mm SF泵入组玻璃体液荧光强度在第1、3、18小时比SF注射组高,差异有显著性(p<0.05)；而6mm FD泵入组玻璃体液荧光强度在各时间点与FD注射组相比,差异均无显著性(p>0.05)；且SF注射组和FD注射组注射器内药物残余量分别为25.00±11.801μL和14.33±5.631μL,两组间比较差别有显著性(p<0.05),表明玻璃体腔药物注射时可能小分子药物较大分子药物更易于在注射器内残留。4.各组视网膜电图暗视视杆反应b波振幅、暗视最大混合反应b波振幅和暗室震荡电位波幅值治疗前,第1次治疗后和第3次治疗后的结果采用重复测量资料的方差分析,均无统计学差异(P>0.05)。各组视网膜组织切片在光学显微镜下未见明显异常,各层细胞完整、结构清晰。结论1.兔眼以合适的速度持续向玻璃体腔泵入药物时能较好的维持眼压平稳,具有良好的耐受性。2.与玻璃体腔药物注射相比,兔眼玻璃体腔药物泵入能较准确地控制药物剂量。3.兔眼玻璃体腔药物泵入进针深度不同时,无论分子量大小,前房和玻璃体的药物浓度均有差别。4.兔眼玻璃体腔药物泵入未发现显著的视网膜的功能和显微结构的损害。更多还原

【Abstract】 Reseach backgroundWith the development of medical level and the progress of life quality, the research, diagnosis and treatment of the posterior eye diseases have reached a new height. With positive local drug therapy to these diseases could improve the prognosis of visual acuity, such as age-related macular degeneration, uveitis, high myopia, diabetic retinopathy, central exudative chorioretinopathy and retinal vascular obstruction. And intravitreal injection becomes one of the most common means in clinical work.Intravitreal injection could make drugs directly effect on the posterior eye, avoid the systemic adverse reactions, and also avoid blood-eye barrier which influences the drug delivery. Thus, it makes more doses of drug reach lesions and achieves good curative effects. But there are some defects of intravitreal injection, such as vitreous hemorrhage, retinal detachment, cataract, endophthalmitis when puncture in the eyeball. For these defects, there are many non-penetrating drug delivery research, such as periocular injection, the suprachoroidal space drug delivery, iontophoresis. Due to the long duration of the ocular diseases and the rapid diffuse of the drugs, intravitreal injection has to be repeated often. Aiming at this problem, there are all sorts of prolong the therapeutic methods of research, such as the scleral plug, intraocular implants, controlled release formulations. In addition, because the eye is a closed system with fixed volume, and is sensitive to an increase in intraocular pressure, drugs must be delivered by injection of small volumes of solution. Even small doses often bring situations with high intraocular pressure, reflux and drug residues. A transient increase in intraocular pressure can lead to ischemia of the optic nerve head and retina, which may bring further damages to patients with pre-existing glaucoma or a history of vascular occlusion. Moreover, drug and vitreous reflux and the residual volume in the syringe related with intraocular pressure elevation lead to the inaccuracy of the drug doses. However, through clinical observation and literature reading, we found that the elevated intraocular pressures are usually dropped to normal in a short time. So we speculate whether the eyes have an efficient intraocular pressure autoregulation mechanism, whether a continuous and chronic drug delivery method could well control of the intraocular pressure. We also envisaged whether by this method could properly increase the dose of drug and improve the accuracy. Therefore, we design animal model using a pump to perform an intravitreal infusion in this study to observe the feasibility and the advantages and disadvantages of this method, to expand the drug delivery methods of the posterior eye.ObjectiveThe aim of this study was to explore the method of intravitreal infusion in rabbits, compare the different ways of drug delivery, observe the drug diffusion and concentration of intravitreal infusion, research the effects of intravitreal infusion on the retinal function and structure.Methods1. The preliminary design of intravitreal infusion:insulin pump was chosen as the infusion pump, chose the matched27G needle and took the0.06%trypan blue (TB) solution for the infusion.24New Zealand rabbit were randomly divided into Group A, B, C, D with6eyes in each group. They were separately infused over30minutes with50,100,150and200μL of TB. Measured the intraocular pressure (IOP) at0,5,10,15,20,25,30minutes and pull out the needle and observed drug reflux, residual volume and eye changes in each group.2. Comparison of different drug delivery methods:according to the results1took the Group B as reference and designed Group E, F, G.18New Zealand rabbits, divided into3groups and6eyes in each group. Each group chose the27G needle with6mm insertion. Group E underwent injection of100μL of TB. Group F was bolus infused with100μL of TB within1minute. Group G was infused with100μL of TB over a period of30minutes. Intraocular pressure (IOP), drug reflux, residual volume and eye changes in each group were observed and compared.3. The drugs concentration of different drug delivery methods and molecular weights:72New Zealand white rabbits were randomly divided into6groups. Each group included24eyes of12animals. The first3 groups with0.01%sodium fluorescein (SF)(molecular weight is376.28) solution for delivery, paired both eyes as infused over30minutes with100μL of SF with4mm insertion (4mm SF infusion group), infused over30minutes with100μL of SF with6mm insertion (6mm SF infusion group), intravitreal injection of100μL of SF with6mm insertion (SF injection group). Eyes of experimental animals were enucleated at the first, third, sixth and eighteenth hours post-operation (6eyes of each time point in each group). Then the aqueous humor and vitreous were collected and the fluorescence intensity was detected. The last3groups with1%fluorescein isothiocyanate-dextran (FD)(molecular weight of150kDa) solution for delivery, paired both eyes as infused over30minutes with100μL of FD with4mm insertion (4mm FD infusion group), infused over30minutes with100μL of FD with6mm insertion (6mm FD infusion group), intravitreal injection of100μL of FD with6mm insertion (FD injection group). Eyes of experimental animals were enucleated on the first, third, ninth and eighteenth days post-operation (6eyes of each time point in each group). Then the aqueous humor and vitreous were collected and the fluorescence intensity was detected.4. The influence of different drug delivery methods for retinal function and structure:42New Zealand white rabbits were randomly divided into7groups. Each group included6eyes. The left eyes of group1were infused over30minutes with100μL of balanced salt solution (BSS) with6mm insertion. The right eyes of group1underwent injection of100μL of BSS. The left eyes of group2were bolus infused with100 μL of BSS within1minute. The right eyes of group2were normal control group.3times treatments were performed on the first, fourth, and seventh days respectively. Electroretinogram (ERG) was performed before the treatment,30minutes after the first and third treatment. Eyes of experimental animals were enucleated on the seventh days and retinal structures were observed under optical microscope.Results:1. The mean IOP during intravitreal infusion for groups A, B, C and D were17.65±2.56,25.19±1.76,29.13±4.38and39.77±8.54mmHg, and the highest IOP during intravitreal infusion were19.44±4.7126.89±2.54,32.78±2.92和48.78±4.53mmHg, respectively. Eyes in all four groups were observed trypan blue in anterior chamber. Part of the group C and all of group D can be observed mild to moderate corneal edema with the increase of IOP.2. The mean IOP post-injection for group E was46.06±7.12mmHg and the residual volume was about10to40μL. The IOP values of group F after bolus infusion were more than60mmHg, but they were less than20mmHg after30minutes. The mean IOP during intravitreal infusion for groups G was25.27±1.85mmHg, and lens damage near the puncture site occurred in two eyes.3. The mean IOP in all eyes with infusion over30minutes with100μL drugs (96eyes) was25.11±3.94mmHg. The fluorescence intensity of aqueous humor at the first, third and sixth hours in4mm SF group compared with6mm SF group and SF injection group has significant difference (p<0.05). The fluorescence intensity of aqueous humor on the first day in4mm FD infusion group compared with6mm FD infusion group and FD injection group has significant difference (p<0.05). They suggest that the shallow insertion make drugs diffused from the anterior chamber easily. The fluorescence intensity of vitreous humor in6mm SF infusion group at the first, third and eighteenth compared with4mm SF infusion group has significant difference (p<0.05). The fluorescence intensity of vitreous humor in6mm FD infusion group on ninth and eighteenth days compared with4mm FD infusion group has significant difference (p<0.05). They suggest that in the insertion depth is associated with the drug concentration of vitreous humor. The fluorescence intensity of vitreous humor in6mm SF infusion group at the first, third and eighteenth hours compared with SF injection group has significant difference (p<0.05). But there were no significant difference between6mm FD infusion group and FD injection group (p>0.05). Moreover, the drug residual volume in SF injection group and the FD injection group were25.00±11.80μL和14.33±5.63μL, comparison between the two groups is significant (p<0.05). These suggest that drugs with small molecular are easier to have residues than larger molecules.4. Each scotopia rod b wave amplitude, scotopic biggest mixed reaction b wave amplitude and the darkroom shock potential amplitude value of ERG in each group before treatment, after the first treatment and after the third treatment results has no statistical difference (P>0.05). Each retina tissue section did not see obvious abnormal under the optical microscope, the cells of each layers are complete and the structures are clear.Conclusions1. Intravitreal infusion with the appropriate speed could keep the IOP stable and have good tolerance in the rabbit eye.2. Compared with intravitreal injection, intravitreal infusion in the rabbit eye could improve the accuracy of actual drug doses.3. No matter what the molecular weight is, when the insertion depth of intravitreal infusion in the rabbit eye has the difference, the drug concentration in anterior chamber and vitreous will be different, too.4. Intravitreal infusion in the rabbit eye has no significant damage to the function and microstructure of the retina.更多还原