OphthalmologyWeb
In a study published in the January 2008 issue of the British Journal of Ophthalmology (BJO), surgeons from the University of Toronto describe their successes in using the "Half-Top-Hat", or HTH, lamellar wound configuration. The technique consists of grafting a donor scleral button with "top-hat" edges into a straight full thickness trephination recipient bed. Authors Kaiserman, Behar, and Rootman conclude that HTH is a valid alternative in penetrating keratoplasty. Aside from being easier to perform, the procedure has advantages including better apposition of donor and recipient corneas, and improved tectonic strength to prevent graft dehiscence.