基于超快光致破裂效应的飞秒激光巩膜造瘘微创手术基础研究

发布时间：2018-08-17 15:25

【摘要】： 目的探索利用飞秒激光的光致破裂效应实施微创性巩膜造瘘术的可行性,并寻求适宜的激光参数和切割方式。方法飞秒激光(800nm/50fs／1kHz)经0.1数值孔径(numerical aperture, NA)的物镜聚焦后扫描离体兔眼水合巩膜。通过计算机控制的精密三维平台的移动,尝试应用不同脉冲能量和曝光时间的飞秒激光对巩膜片的多种切割方式。应用扫描电镜对飞秒激光作用后的巩膜组织进行形态学观察和测量。结果飞秒激光能够在离体兔眼巩膜上完成包括线性切割,柱形孔隙和矩形空腔在内的三种切口。当脉冲能量在37.5-150μJ的范围内变化时,飞秒激光以0.025-0.1mm/s的速度线性扫描巩膜后均能在巩膜表面产生光致破裂效应。而当脉冲能量低于31.25μJ,功率密度低于4.06×1014 W／cm2的阈值水平时,受飞秒激光辐射的巩膜组织在扫描电镜下不会产生任何形态学改变。飞秒激光在巩膜表面产生的线性切口深度与激光的脉冲能量以及曝光时间呈正相关。扫描电镜显示飞秒激光在巩膜表面产生的切口具有精确的几何形状并且切口边缘光滑整齐,切口周围组织未见明显的附带损伤。结论飞秒激光对离体兔眼巩膜高精度、微创伤的光致破裂效应,预示了它在抗青光眼的巩膜造瘘术中有着潜在的应用价值。目的探索飞秒激光经外路巩膜造瘘的可行性,评价手术的有效性和安全性。方法对20只青紫蓝兔右眼后房注射α-糜蛋白酶,制备兔慢性高眼压模型。将兔随机分为实验组和对照组,每组10只兔。实验组右眼行飞秒激光巩膜造瘘术,对照组右眼不做手术治疗。飞秒激光脉宽50fs,波长800nm,重复频率1kHz,脉冲能量0.4mJ。观察术后1个月内滤过泡形态、眼压及并发症情况,组间眼压比较采用重复测量方差分析。分别于术后第3、7、14、30天对滤过道组织进行光镜观察,术后14天对滤过道组织进行扫描电镜观察。结果10只兔眼巩膜均被飞秒激光一次性穿透性切除,激光作用时间为15s-16s,巩膜切口约2mm×1mm2。术后第1、3、7、14、21、30天,实验组和对照组眼压比较,差异具有统计学意义(F=117.46,39.96,15.17,11.62,15.31,11.10；P0.01)。除2眼因激光在切穿巩膜时损伤虹膜根部导致前房出血外,未见其他明显的手术并发症。术后第1天所有实验眼均有滤过泡形成,到第3天滤过泡隆起度最高。随后滤过泡逐渐缩小,泡壁增厚,第3周时滤过泡逐渐扁平消失。病理学检查显示飞秒激光巩膜造瘘的切口光滑锐利,对周围组织的附带损伤小,术后滤过道的修复反应主要表现为成纤维细胞的轻度增生和薄层疏松胶原纤维的形成。结论飞秒激光经外路巩膜造瘘术简便快捷,安全有效,有可能成为治疗青光眼的一种新的手术方法。目的比较经外路飞秒激光巩膜造瘘术和机械刀巩膜造瘘术的手术效果和滤过道创伤修复反应,探讨飞秒激光巩膜造瘘术的有效性和优越性。方法实验研究。20只青紫蓝兔随机分为两组,每组各10只兔。一组右眼行飞秒激光巩膜造瘘术,另一组右眼行机械刀巩膜造瘘术,左眼作为非手术对照眼。观察术后1个月内滤过泡表现、眼压变化及手术并发症情况。另有6只兔,随机选择右眼行飞秒激光巩膜造瘘术,左眼行机械刀巩膜造瘘术,术后第14天处死,采用HE染色、Masson三色染色、免疫组化和扫描电镜技术,观察滤过道的创伤修复反应。飞秒激光脉宽50fs,波长800nm,重复频率1kHz,脉冲能量0.4mJ。本研究中的等级资料和分类计数资料采用两独立样本非参数检验,手术成功率的比较采用Kaplan-Meier法。结果16只兔眼巩膜均被飞秒激光一次性穿透性切除,激光作用时间为15s-16s。飞秒激光组19%(3／16)的术眼因激光误伤虹膜导致前房少量出血,50%(8／16)的术眼手术区周边角膜出现水肿混浊。飞秒激光巩膜造瘘术后功能性滤过泡的生存时间以及眼压下降的持续时间均较机械刀组明显延长,差异有统计学意义(Mann-WhitneyU值=24.000,20.000；P=0.025,0.016)。飞秒激光组的手术成功率明显高于机械刀组,差异有统计学意义(χ2=7.785,P=0.005)。病理学检查显示术后第14天,机械刀组的巩膜切口及结膜下间隙已被致密的纤维结缔组织完全阻塞,而飞秒激光组的滤过道则基本保持通畅,结膜下仍见大范围滤过间隙存在。术后第14天,飞秒激光组滤过道内新生胶原纤维量、成纤维细胞量和新生血管量均少于机械刀组,差异均有统计学意义(Mann-WhitneyU值=7.000,5.500,2.500；P=0.036,0.045,0.013)。结论飞秒激光巩膜造瘘术有可能成为一种安全有效,方便快捷的新型微创性抗青光眼手术方式。
[Abstract]:Objective To explore the feasibility of minimally invasive scleral fistula with femtosecond laser photorupture effect, and to find suitable laser parameters and cutting methods.
Methods Femtosecond laser (800 nm/50 fs/1 kHz) was focused by 0.1 numerical aperture (NA) objective lens and then scanned the hydration sclera of rabbit eyes in vitro. The sclera tissue after second laser treatment was observed and measured.
Results Femtosecond laser can perform three kinds of incisions including linear incision, cylindrical cavity and rectangular cavity on the sclera of rabbits in vitro. When the pulse energy changes in the range of 37.5-150 uJ, the sclera can be linearly scanned by femtosecond laser at the speed of 0.025-0.1 mm/s and the sclera surface can produce photorupture effect when the pulse energy is low. The scleral tissue irradiated by femtosecond laser has no morphological changes under scanning electron microscope when the power density is below the threshold level of 4.06 *1014 W/cm 2 at 31.25 uJ. The linear incision depth produced by femtosecond laser on the scleral surface is positively correlated with the laser pulse energy and exposure time. The scleral incision has precise geometry and smooth edge, and there is no obvious incidental damage to the surrounding tissue.
Conclusion Femtosecond laser has high precision and micro-traumatic photorupture effect on isolated rabbit sclera, which indicates that it has potential application value in anti-glaucoma scleral fistula.
Objective to explore the feasibility of femtosecond laser through external scleral fistulas and evaluate the effectiveness and safety of the operation.
Methods Twenty rabbits were injected with alpha-chymotrypsin into the posterior chamber of the right eye and divided into experimental group and control group randomly, 10 rabbits in each group. The morphology of filtering blebs, intraocular pressure and complications were observed one month after operation. The intraocular pressure between groups was compared by repeated analysis of variance.
Results The sclera of all 10 rabbits were resected by femtosecond laser. The duration of laser treatment was 15s-16s, and the scleral incision was about 2mm *1mm 2. The intraocular pressure of the experimental group and the control group was significantly different (F = 117.46, 39.96, 15.17, 11.62, 15.31, 11.10; P 0.01). There were no significant surgical complications except for anterior chamber hemorrhage at the iris root. On the first day after operation, all the experimental eyes had bleb formation, and the bleb swelling was the highest on the third day. The repairing reaction of the filter passage was mainly manifested by mild proliferation of fibroblasts and formation of thin-layer loose collagen fibers.
Conclusion Femtosecond laser sclerostomy is a simple, rapid, safe and effective method for the treatment of glaucoma.
Objective To compare the effect of external femtosecond laser sclerostomy with mechanical scalpel sclerostomy and repair reaction of filtering tract wound, and to explore the effectiveness and superiority of femtosecond laser sclerostomy.
Methods Twenty blue and blue rabbits were randomly divided into two groups, 10 rabbits in each group. One group underwent femtosecond laser sclerostomy on the right eye, the other underwent mechanical scalpel sclerostomy on the right eye, and the other underwent non-operative control on the left eye. Femtosecond laser sclerostomy was performed on the left eye and mechanical scalpel sclerostomy was performed on the 14th day after operation. HE staining, Masson trichrome staining, immunohistochemistry and scanning electron microscopy were used to observe the wound healing response of the filter passage. Two independent sample nonparametric tests were used to count data. Kaplan-Meier method was used to compare the success rate of operation.
Results The sclera of all the 16 rabbits were resected by femtosecond laser for 15s-16s. In the femtosecond laser group, 19% (3/16) of the eyes suffered from a small amount of bleeding in the anterior chamber and edema and turbidity in the cornea around the operation area of 50% (8/16) of the eyes. The survival time of the functional filtering blebs after femtosecond laser scleral fistulation. The duration of IOP decrease was significantly longer in the femtosecond laser group than in the mechanical knife group (Mann-Whitney U = 24.000,20.000; P = 0.025,0.016). The success rate in the femtosecond laser group was significantly higher than that in the mechanical knife group (2 = 7.785, P = 0.005). Pathological examination showed sclerectomy in the mechanical knife group on the 14th day after surgery. The oral cavity and subconjunctival space were completely blocked by dense fibrous connective tissue, while the filtering passage of femtosecond laser group remained unobstructed, and large-scale subconjunctival filtering space was still found. Academic significance (Mann-WhitneyU value =7.000,5.500,2.500; P=0.036,0.045,0.013).
Conclusion Femtosecond laser sclerostomy may be a safe, effective, convenient and new minimally invasive surgery for glaucoma.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：R779.6

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