Which of these instruments would be used during a keratoplasty?

In the context of keratoplasty, which involves the surgical transplantation of the cornea, the Cottingham punch is specifically designed for this procedure. This instrument is utilized to create a precise circular cut in the cornea, allowing for the removal of the damaged portion for replacement with donor tissue. Its design enables surgeons to achieve the necessary control and accuracy during the delicate process of preparing the corneal graft.

The other instruments, while they may have their applications in ophthalmic or other surgical procedures, do not serve the same direct role in keratoplasty. The Kilner hook is typically used for manipulating tissue during cataract surgery, the Bowman probe is employed for probing the tear duct system, and the Kerrison rongeur is used for removing bone or tissue in neurosurgical or orthopedic procedures. Therefore, the Cottingham punch stands out as the appropriate choice for performing a keratoplasty, reflecting its specialized purpose and design for corneal surgery.