What tissue is transplanted during a penetrating corneal transplant surgery?

The correct answer, which states that a full thickness cornea is transplanted during penetrating corneal transplant surgery, emphasizes the comprehensive nature of this type of procedure. In a penetrating keratoplasty, the entire thickness of the cornea is removed and replaced with donor corneal tissue. This encompasses all layers of the cornea – including the epithelium, stroma, and endothelium. The purpose of this technique is to restore vision and improve the structural integrity of the cornea when it has become severely damaged, diseased, or clouded.

Choosing to transplant the full thickness ensures that all layers are addressed, as issues can often exist at various depths due to the underlying pathology. Only transplanting specific layers, such as the anterior or posterior cornea, would not resolve the potential issues associated with deeper corneal damage, which is why those options do not represent the method used for penetrating keratoplasty. Understanding the comprehensive nature of the transplant procedure is crucial for grasping how corneal diseases are effectively treated in surgical settings.