The pre-Descemet's layer/Dua's layer, also termed the Dua-Fine layer and the pre-posterior limiting lamina layer, lies anterior to the Descemet's membrane in the cornea, is 10 μm (range 6–16) thick, made predominantly of type I and some type VI collagen with abundant elastin, more than any other layer of the cornea. It has high tensile strength (bursting pressure up to 700 mm of Hg), is impervious to air and almost acellular. At the periphery it demonstrates fenestrations and ramifies to become the core of the trabecular meshwork, with implications for intraocular pressure and glaucoma. It has been demonstrated in some species of animals.

The layer has assumed considerable importance in anterior and posterior lamellar corneal transplant surgery by improving our understanding of the behaviour of corneal tissue during these procedures, improved techniques and made the surgery safer with better outcomes. It has led to the innovation of new surgical procedures namely, pre-Descemet's endothelial keratoplasty, suture management of acute hydrops, DALK-triple and Fogla's mini DALK.

The discovery and knowledge of the layer has introduced paradigm shifts in our age old concepts of Descemet's membrane detachment, acute corneal hydrops in keratoconus and Descemetoceles, with impact on management approaches. It has been shown to contribute to the pathology and clinical signs observed in corneal infections and some corneal dystrophies. Early evidence suggests that it may have a role in the pathogenesis of keratoconus in relation to its elastin content. Its contribution to corneal biomechanics and glaucoma are subjects of current investigations.

前后弹力层/Dua 层，也称为 Dua-Fine 层和前后限制层，位于角膜中后弹力层之前，厚度为 10 μm（范围 6-16），主要由 类型制成I 和一些 VI 型胶原蛋白含有丰富的弹性蛋白，比角膜的任何其他层都多。它具有高拉伸强度（爆破压力高达 700 毫米汞柱），不透气且几乎无细胞。在外围，它表现出开窗和分支，成为小梁网的核心，对眼内压和青光眼有影响。它已在某些动物物种中得到证实。

通过提高我们对手术过程中角膜组织行为的理解，改进技术并使手术更安全，效果更好，该层在前板层和后板层角膜移植手术中占据了相当重要的地位。它导致了新外科手术的创新，即前后弹力层内皮角膜移植术、急性积水缝合处理、DALK-triple 和 Fogla 的迷你 DALK。

该层的发现和知识使我们古老的后弹力层分离、圆锥角膜和后弹力层突出的急性角膜积水概念发生了范式转变，并对治疗方法产生了影响。它已被证明有助于在角膜感染和一些角膜营养不良中观察到的病理学和临床体征。早期证据表明，它可能在圆锥角膜的发病机制中发挥作用，与其弹性蛋白含量有关。它对角膜生物力学和青光眼的贡献是当前研究的主题。