LAUSR

Dear Editor, Today, split cornea technique is an established procedure and is mostly used for two recipients by combining deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK) surgeries [1–7]. However, for some surgical interventions including block excision with tectonic corneoscleral grafting, split cornea procedure is not planned regularly up to now [5, 8]. In the run-up for this procedure, normally a donor cornea with a bigger scleral ring is gained. Nonetheless, the preparation of the tectonic graft for covering the corneoscleral defect after block excision results in a rest donor cornea transplant which is normally too small for further regular size penetrating keratoplasties (PKs) or combined DALK/DMEK surgeries. However, using a modified donor transplant trephination technique, a corneoscleral transplant for regular size keratoplasties can be gained, also after preparation of a tectonic graft for block excision. Herein, we describe shortly this novel donor preparation technique, the differences compared to the standard procedure, possible applications, and the advantages and disadvantages for the first time. Commonly for standard donor preparation (i.e., corneal grafts for DMEK, DALK, or PK except block excision), most cornea banks perform a central scleral trephination using a trephine with 15.5 mm diameter (Fig. 1A) [9]. For a block excision with a tectonic corneoscleral graft, a donor transplant with a bigger scleral ring is necessary. Therefore, usually, a central donor eye trephination is performed using a 17.5-mm trephine to gain a suitable corneoscleral grafting for this procedure (without regular size corneal splitting) (Fig. 1B). However, a decentral donor eye trephination also using a 17.5-mm trephine results in a corneoscleral donor transplant (Fig. 1C) which can be used both for block excision with tectonic corneoscleral graft and regular size penetrating keratoplasty or combined DALK and DMEK. Key messages