RT Journal Article SR Electronic T1 New trephine for keratoplasty with interchangeable blade. JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 919 OP 919 DO 10.1136/bjo.56.12.919 VO 56 IS 12 A1 H Soriano A1 A Canossa YR 1972 UL http://bjo.bmj.com/content/56/12/919.abstract AB