Donor Tissue Preparation for Bowman Layer Transplantation

Abstract

Isolated BL grafts can be prepared from both whole donor globes and corneoscleral rims with equivalent success. Preparation from corneoscleral rims may offer the advantage that, from one donor cornea, the posterior layers can be used for Descemet membrane endothelial keratoplasty graft preparation and the anterior part for BL graft preparation.

Bowman layer transplantation in the treatment of keratoconus

“…BL graft preparation was initially described in 2010 [ 22 ], and has remained largely unchanged since: BL grafts can either be prepared from whole donor globes (obtained less than 24 h postmortem, with corneas considered ineligible for PK) or from an anterior corneal button after stripping the Descemet membrane and endothelium for use in patients who were indicated for Descemet Membrane Endothelial Keratoplasty (DMEK) [ 23 ]. Donor globes or anterior corneal buttons (epithelial side up) are mounted on a globe holder or artificial anterior chamber, respectively, and the epithelium is removed using surgical spears (Fig.…”

“…The peripheral BL can be lifted and grasped with a McPherson forceps and then carefully peeled free from the underlying stroma, obtaining a 9- to 11-mm diameter BL graft (Fig. 1 ) [ 23 ]. Due to the inherent elasticity of the tissue, BL grafts tend to curl into a single or double roll with the epithelial border at the outside (Fig.…”

“…1 ). In the end, the donor BL graft is rinsed in 70% alcohol for 30 s and stored in organ-culture medium until the time of transplantation [ 23 ].

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Bowman’s layer transplantation: evidence to date

“…It can harvested from either whole donor globes mounted on a holder (technique I), or corneoscleral rims mounted on an artificial chamber (technique II). 28 …”

“…Rates of successful harvesting of BL were comparable between whole globes and corneoscleral rims (69.4% [25/36] and 72.2% [26/36] for techniques I and II, respectively). 28 Tearing of the BL during preparation, and an unusually thick graft were the main reasons for discarding the donor BL grafts. Imprecise surgical manipulations may yield either a thick BL graft or may lead to penetration/buttonholing of BL.…”