Trephine refers to a round or cylindrical saw, a surgical device used to cut away circular portions of tissue, such as corneal tissue or bone. A surgical trephine is a device with a cylindrical blade that can vary depending on the purpose of use. It is used to alleviate pressure beneath the surface by cutting away a spherical skull bone. These trephines are roughly classified into two types: those with suction and those without. Suctionless trephines surgical instrument is made out of a cylindrical metal blade with a sharp end and a blunt on the other end. These blades are placed between the surgeon's two fingers, generally the thumb and index finger, and twisted clockwise and counterclockwise to cut the recipient corneal tissue. It is safe to use on both donor and recipient corneas. Although suction-less surgical trephines can be used effectively on uneven, scarred host corneas, suction trephines may fail to produce good suction. These suction-less trephines can be used with or without a handle. During the trephination of the corneal tissue, suction trephines are kept in place by the vacuum and steadied by the surgeon's fingers. Suction trephines used by corneal surgeons include the Barron radial vacuum trephine and the Hanna trephine. You can check trephine from reputable manufacturers like pyrax, AmazeSurgical, PMW, Dude, Medichem, and many more.