Parthasarathy Anand, Por Yong Ming, Tan Donald T H
Singapore National Eye Center, 11, Third Hospital Avenue, Singapore.
Br J Ophthalmol. 2007 Oct;91(10):1369-73. doi: 10.1136/bjo.2006.113357.
To describe a quick and simple "small-bubble" technique to immediately determine the success of attaining complete Descemet's membrane (DM) separation from corneal stroma through Anwar's "big-bubble" technique of deep anterior lamellar keratoplasty (DALK) for complete stromal removal.
A partial trephination was followed by a lamellar dissection of the anterior stroma. Deep stromal air injection was then attempted to achieve the big bubble to help separate the stroma from the DM. To confirm that a big bubble had been achieved, a small air bubble was injected into the anterior chamber (AC) through a limbal paracentesis. If the small bubble is then seen at the corneal periphery, it confirms that the big-bubble separation of DM was successful because the convex nature of the bubble will cause it to protrude posteriorly, forcing the small AC bubble to the periphery. If the small AC bubble is not seen in the corneal periphery, this means that it is present in the centre, beneath the opaque corneal stroma, and therefore the big bubble has not been achieved.
We used the small-bubble technique to confirm the presence of the big bubble in three (one keratoconus, one interstitial keratitis and one dense corneal scar) out of 41 patients who underwent DALK. The small-bubble technique confirmed that the big bubble was achieved in the eye of all three patients. Complete stromal removal with baring of the DM was achieved, and postoperatively all three eyes achieved best corrected vision of 6/6.
The small-bubble technique can be a useful surgical tool for corneal surgeons attempting lamellar keratoplasty using the big-bubble technique. It helps in confirming the separation of DM from the deep stroma, which is important in achieving total stromal replacement. It will help to make the transition to lamellar keratoplasty smoother, enhance corneal graft success and improve visual outcomes in patients.
描述一种快速简便的“小气泡”技术，用于通过安瓦尔的深前板层角膜移植术（DALK）的“大气泡”技术立即确定从角膜基质完全分离Descemet膜（DM）以实现完全基质去除的成功与否。
先进行部分环钻，然后进行前基质的板层分离。接着尝试进行深层基质空气注射以形成大气泡，帮助将基质与DM分离。为确认已形成大气泡，通过角膜缘穿刺向前房（AC）注入一个小气泡。如果随后在角膜周边看到小气泡，则证实DM的大气泡分离成功，因为气泡的凸面会使其向后突出，将前房小气泡挤到周边。如果在角膜周边未看到前房小气泡，这意味着它位于中央、不透明角膜基质下方，因此尚未形成大气泡。
在41例行DALK的患者中，我们使用小气泡技术在3例患者（1例圆锥角膜、1例间质性角膜炎和1例致密角膜瘢痕）中确认了大气泡的存在。小气泡技术证实这3例患者的眼中均形成了大气泡。实现了完全去除基质并暴露DM，术后这3只眼的最佳矫正视力均达到了6/6。
小气泡技术对于尝试使用大气泡技术进行板层角膜移植的角膜外科医生而言可能是一种有用的手术工具。它有助于确认DM与深层基质的分离，这对于实现完全基质置换很重要。它将有助于使向板层角膜移植的过渡更顺利，提高角膜移植成功率并改善患者的视觉效果。
