發(fā)布時(shí)間：2018-09-10 11:30

【摘要】：目的以核黃素-紫外線A角膜膠原交聯(lián)（corneal collagen cross-linking，CXL）術(shù)后兔眼角膜基質(zhì)細(xì)胞和膠原纖維作為觀察對象，通過了解CXL術(shù)后角膜基質(zhì)細(xì)胞和膠原纖維的變化規(guī)律，探討角膜膠原纖維重塑在CXL術(shù)后生物力學(xué)穩(wěn)定性的作用；初步評價(jià)CXL治療進(jìn)展期圓錐角膜的安全性、有效性。 方法1.健康新西蘭白兔15只，隨機(jī)分為3組，右眼行CXL手術(shù)，左眼為正常對照，分別于術(shù)后1d、7d、4w取兔眼角膜，行HE和a-SMA染色、TUNEL法檢測細(xì)胞凋亡。2.對CXL術(shù)后角膜行苦味酸天狼星紅染色和角膜應(yīng)力-應(yīng)變測量，記錄CXL術(shù)后膠原蛋白成分的變化、最大載荷、最大應(yīng)力和彈性模量。3.選擇13例(22只眼)進(jìn)展期圓錐角膜,接受CXL治療，于術(shù)前和術(shù)后1月、3月、6月和12個(gè)月復(fù)查，檢查指標(biāo)包括視力、角膜地形圖、角膜活體共焦鏡和角膜內(nèi)皮計(jì)數(shù)等。 結(jié)果1.正常角膜基質(zhì)主要為致密結(jié)締組織，角膜基質(zhì)細(xì)胞散在分布于其中。CXL術(shù)后1d，術(shù)區(qū)基質(zhì)中僅偶見基質(zhì)細(xì)胞，角膜上皮細(xì)胞和基質(zhì)細(xì)胞均可見大量凋亡細(xì)胞。術(shù)后7d，角膜基質(zhì)細(xì)胞水腫、數(shù)量減少，角膜基質(zhì)細(xì)胞和上皮細(xì)胞凋亡數(shù)量均較術(shù)后1d減少。術(shù)后4w，角膜基本保持正常厚度，角膜基質(zhì)細(xì)胞和上皮細(xì)胞凋亡數(shù)量顯著減少。術(shù)后7d和4w，角膜基質(zhì)見部分細(xì)胞a-SMA染色呈陽性。2.正常角膜基質(zhì)可見分布均勻、以紅色為主的I型膠原，其間可見少量纖細(xì)、綠色的Ⅲ型膠原；術(shù)后7d，Ⅲ型膠原纖維明顯增多，且纖維明顯變粗；術(shù)后4w，Ⅲ型膠原纖維顯著增多粗大，與I型膠原間雜分布。CXL術(shù)后不同觀察時(shí)期角膜的彈性模量均較正常對照組增加。CXL術(shù)后1d橫向比縱向彈性模量增加的量有統(tǒng)計(jì)學(xué)差異。3.圓錐角膜患者接受CXL術(shù)后12個(gè)月裸眼視力和最佳矯正視力分別較術(shù)前提高0.115±0.158LogMAR單位和0.114±0.218LogMAR單位。術(shù)后12個(gè)月Kmax值和散光分別較術(shù)前降低1.893±3.713D和0.117±1.488D。角膜厚度術(shù)后1月時(shí)減少27.5±26.8μm，術(shù)后12個(gè)月時(shí)角膜厚度與術(shù)前相比無統(tǒng)計(jì)學(xué)顯著性差異。術(shù)后角膜內(nèi)皮、眼壓、晶狀體和眼底無明顯變化。 結(jié)論1.CXL術(shù)后兔眼角膜基質(zhì)細(xì)胞主要通過凋亡途徑明顯減少，周圍基質(zhì)細(xì)胞通過增殖補(bǔ)充凋亡的基質(zhì)細(xì)胞的丟失，新生基質(zhì)細(xì)胞通過活化形成成肌纖維細(xì)胞參與到角膜基質(zhì)的重塑。2.CXL術(shù)后角膜各型膠原比例、分布發(fā)生改變，，提示角膜基質(zhì)膠原纖維發(fā)生重塑，CXL可以長期增加角膜的生物力學(xué)強(qiáng)度，其效應(yīng)的維持可能與膠原纖維的重塑有關(guān)。3.CXL可以阻止進(jìn)展期圓錐角膜病變發(fā)展，在1年的隨訪期內(nèi)可觀察到視力和角膜地形圖的指標(biāo)的改善，CXL將是治療進(jìn)展期圓錐角膜一個(gè)安全有效的方法。
[Abstract]:Objective to investigate the changes of corneal stromal cells and collagen fibers in rabbit eyes after riboflavin-ultraviolet A corneal collagen cross-linking (corneal collagen cross-linking,CXL). To investigate the role of corneal collagen remodeling in biomechanical stability after CXL and to evaluate the safety and efficacy of CXL in the treatment of advanced keratoconus. Method 1. Fifteen healthy New Zealand rabbits were randomly divided into 3 groups. The right eye underwent CXL operation and the left eye was the normal control. The cornea of the rabbits were taken at 1 day, 7 days and 4 weeks after operation. Apoptosis was detected by HE and a-SMA staining with Tunel. Sirius red staining and corneal stress-strain measurement were performed on the cornea after CXL. The changes of collagen composition, maximum load, maximum stress and modulus of elasticity were recorded after CXL. Thirteen cases (22 eyes) of advanced keratoconus were selected and treated with CXL. They were reexamined before and after operation at 1 month, 3 months, 6 months and 12 months. The examination indexes included visual acuity, corneal topography, corneal confocal lens and corneal endothelium count. Result 1. The normal corneal stroma was mainly dense connective tissue. Corneal stromal cells were scattered in the corneal stromal cells. Only stromal cells were occasionally seen in the stroma of the operation area. A large number of apoptotic cells were found in corneal epithelial cells and stromal cells. On the 7th day after operation, the number of corneal stromal cells decreased and the number of corneal stromal cells and epithelial cells apoptosis decreased. After 4 weeks, the corneal thickness remained normal, and the number of corneal stromal cells and epithelial cells apoptosis decreased significantly. At 7 days and 4 weeks after operation, some of the corneal stroma cells were positive for a-SMA staining. The normal corneal stroma was evenly distributed, with a small amount of fine and green type 鈪

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