角膜后弹力层剥除自动角膜刀取材内皮移植手术的方法和体会

Descemet's stripping automated endothelium keratoplasty

角膜后弹力层剥除自动角膜刀取材内皮移植术(DSAEK)已经成为替代穿透性角膜移植治疗角膜内皮病变的首选术式,其优点为仅去除病变的角膜内皮和后弹力层,最大限度地保持角膜的完整性,避免眼表面的损伤和明显的屈光变化。手术方法为在角膜缘部制备5mm的隧道切口,用后弹力膜剥离钩划开并剥除病变的角膜后弹力层和内皮层,同时移植带有部分角膜后基质的后弹力层和内皮层,经前房注气展开并顶起植片使之与植床贴附,无缝线,避免了角膜散光。手术中及术后重要的环节和经验是:亚洲人的前房较浅,在植片植入和展开的环节会有一些问题,因此术前要充分降低眼压,防止术中晶状体虹膜隔的前移,使前房内有较充足的空间植入植片;手术后植片脱位是DSAEK的最大并发症,往往也是导致手术失败的主要原因,避免的方法为术中尽量减少黏弹剂的应用,在植片植入前将前房内的黏弹剂彻底冲洗干净,在植片与植床贴附后要尽量排除二者之间的液体,增加二者的贴附力。晶状体虹膜隔的完整性与气泡能否在前房内持续保持有密切的关系,如果晶状体虹膜隔不完整,气泡容易进入玻璃体腔,无法顶住植片,容易导致植片的脱位,因此早期在手术适应证的选择上要注意这些方面的问题。

Descemet＇s stripping automated endothelium keratoplasty （DSAEK） has gained popularity in the surgical treatment of endothelial disorder as an alternative to penetrating keratoplasty. Selective transplantation of endothelial layer avoids the potential complications. Instead, there is structural integrity for the recipient, minimal change in refraction, and faster recovery of vision. The procedure is that： A 5 mm scleral tunnel incision was made, a special hook was used to score the descemetorhexis and strip off the recipient Descemet＇s membrane and endothelium, and the donor butten with part posterior stroma, Descemet membrane and endothelium was insert to anterior chamber. Filtered air then was injected to force the apposition of the posterior donor stroma to the recipient stromal bed. The surgery no suture and avoid the astigmatism post-operation. The key procedures and experiences during and post operation are that： We often meet some problem in insertion and unfold of donor button because of shallow anterior chamber in Asia. The important measure is that to reduce intraocular pressure, to avoid the anterior removal of lens-iris diaphragm and provide larger place of anterior chamber. Dislocation of donor graft is common complication, it often induce surgery failure in DSAEK. The prevent measure is that： To decrease the amount of viscoelastic and remove completely viscoelastic before insertion of donor graft. To remove the interface liquid between recipient bed and donor graft, to increase both adherence. The integrity of lens-iris diaphragm is a very important factor to maintain the stable air bubble in anterior chamber, otherwise the air bubble easily enter into vitreous cavity to loss the support the donor graft. So the indication should be caution to choice in beginning stage.