Deep anterior lamellar keratoplasty (DALK) is considered a valuablealternative to penetrating keratoplasty (PK) for treatingcorneal disordersthat do not involve theendothelium. DALK preserves the host endothelium, eliminating the risk of endothelial rejection and reducing the risk of late graft failure due to endothelial decay. Despite its not recent introduction, DALK has been considered a difficult, lengthy, and poorly reproducible procedure, limiting its adoption worldwide. With the introduction of the big-bubble technique (BBT) the reproducibility and the time required to complete the procedure were significantly improved, encouraging many surgeons to approach DALK. With BBT air is injected into the stroma to induce separation between the layers of the cornea, facilitating the separation of the diseased or scarred stroma from the healthy endothelium; this allows the creation of a graft-host interface of pristine optical quality, granting clinical results equal to those obtained with PK.Understanding the anatomy and physics behind the big bubble (BB) formation is crucial for thesurgical success of this technique. The discovery of the pre-Descemet's layer (Dua's layer)played a significant role in understanding the principles behindBBformation, considerablyimpacting the safety and reproducibility of the technique. BB formation is influenced by preoperative pathology, trephination size, and instruments used for air injection.Continue advancements have helped to refine BBT's efficacy and reproducibility, broadening its applicability in corneal transplantation whenever the endothelium is healthy.This review provides a detailed account of the procedural steps involved in DALK using the BBT, addressing the most common challenges, highlightingtechnical innovations, and handlingthe most frequent complications.

中文翻译：

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大气泡 DALK：一种进化的技术


深前板层角膜移植术 （DALK） 被认为是穿透性角膜移植术 （PK） 的一种有价值的替代方案，用于治疗不涉及内皮的角膜疾病。DALK 保留宿主内皮，消除了内皮排斥的风险，并降低了由于内皮腐烂导致晚期移植物失败的风险。尽管最近才引入，但 DALK 一直被认为是一种困难、漫长且可重复性差的程序，限制了其在全球范围内的采用。随着大气泡技术 （BBT） 的引入，可重复性和完成手术所需的时间得到了显着提高，鼓励许多外科医生使用 DALK。使用 BBT 将空气注入基质中以诱导角膜层之间的分离，促进患病或疤痕基质与健康内皮的分离;这允许创建具有原始光学质量的移植物-宿主界面，从而获得与 PK 相同的临床结果。了解大气泡 （BB） 形成背后的解剖学和物理学对于该技术的外科手术成功至关重要。前后弹力层 （Dua's layer） 的发现在理解 BBformation 背后的原理方面发挥了重要作用，极大地影响了该技术的安全性和可重复性。BB 的形成受术前病理、环钻大小和用于空气注射的器械的影响。持续的进步有助于提高 BBT 的疗效和可重复性，扩大了其在角膜移植中内皮健康时的适用性。这篇综述详细介绍了使用 BBT 进行 DALK 所涉及的程序步骤，解决了最常见的挑战，强调了技术创新，并处理了最常见的并发症。