Cornea and Refractive Services, Aravind Eye Hospital, Tirunelveli, Tamil Nadu, India.
Indian J Ophthalmol. 2022 Jul;70(7):2777. doi: 10.4103/ijo.IJO_1428_22.
This video demonstrates a useful technique of keratoplasty which can be routinely undertaken by all surgeons when imaging modalities such as anterior segment optical coherence tomography are not available and prior patient history is not forthcoming.
To demonstrate a technique of lamellar separation and layer by layer removal of host cornea when dealing with keratoplasty in perforated corneal ulcers, adherent leucomas, dense corneal opacities, which obscure visualization of the iris and anterior chamber details.
In this video, we demonstrate penetrating keratoplasty in a failed opacified graft with iridocorneal adhesions, with no visualization of anterior chamber details. Lamellar dissection of the host cornea is done starting at its periphery and moving centrally, with gentle peeling of the superficial layers, the epithelium and bulk of stroma, following which, the deeper portion of the cornea is dissected and separated from underlying adherent iris tissue. Layer by layer separation allows better visualization through the remaining thin layers of the cornea. This permits fine dissection and layered removal of the cornea, thereby avoiding injury to iris and lens. Debulking of the host cornea decreases the force that is needed to be applied to separate adherent iris tissue from the host cornea, and reduces the chances of sudden entry into the anterior chamber and subsequent damage to the iris or lens. This also reduces the chance of iris tears, iridodialysis and bleeding from the iris and helps maintain iris integrity, which is essential intraoperatively for protection of lens and anterior chamber formation, and to avoid glare and photophobia postoperatively. Preventing iris damage also reduces the chances of formation of peripheral anterior synechiae (PAS), which can predispose to graft rejection, graft failure and secondary glaucoma.
Layer by layer corneal separation beginning inside the graft host junction, careful separation of iridocorneal adhesions and PAS is a helpful technique to optimally preserve the anterior segment anatomy during difficult cases of penetrating keratoplasty.
当没有眼前节光学相干断层扫描等成像方式，且无法获取患者既往病史时，本视频演示了一种角膜移植术的实用技术，所有外科医生都可以常规采用。
当处理穿透性角膜溃疡、粘连性白斑、致密性角膜混浊等导致虹膜和前房细节无法可视化的病例时，演示一种角膜板层分离和逐层去除宿主角膜的技术。
在本视频中，我们演示了一例因虹膜角膜粘连而混浊的失败移植片的穿透性角膜移植术，无法观察前房细节。从角膜周边开始行宿主角膜板层分离，向中央移动，轻柔地剥除浅层的上皮和基质大部分，然后分离和分离深层角膜与粘连的虹膜组织。分层分离允许通过剩余的薄角膜层更好地可视化。这可实现对角膜的精细解剖和分层去除，从而避免对虹膜和晶状体造成损伤。宿主角膜去肿可减少分离粘连的虹膜组织与宿主角膜所需的力，降低虹膜和晶状体突然进入前房并随后受损的风险。这也减少了虹膜撕裂、虹膜脱离和虹膜出血的机会，并有助于保持虹膜完整性，这对于术中保护晶状体和前房形成以及避免术后眩光和畏光至关重要。防止虹膜损伤还可降低形成周边前粘连（PAS）的机会，PAS 可导致移植物排斥、移植物失败和继发性青光眼。
从移植片宿主交界处开始的角膜分层分离，小心分离虹膜角膜粘连和 PAS，是在困难的穿透性角膜移植病例中优化保护眼前节解剖结构的有用技术。
