[Method for obtaining a pre-Descemet's stromal layer graft]

The discovery of the air-impermeable pre-Descemet's layer prompted discussions on revising the microanatomy of the cornea, enabled classification of the DALK (deep anterior lamellar keratoplasty) technique based on the location of the bubble relative to the pre-Descemet's layer (PDL), and led to the introduction of a new type of Descemet membrane transplantation - pre-Descemet's endothelial keratoplasty (PDEK). We believe that if it is possible to isolate the PDL, then it can be used it as an analogue (or imitation) of the corneal epithelial basement membrane to separate epithelial and stromal cell populations in the treatment of corneal pathology.

This study presents a method for obtaining a PDL graft from the corneal stroma for subsequent clinical use (transplantation through sutureless covering of the cornea).

Fifteen donor corneoscleral buttons were used, including five cryopreserved ones. In all 15 corneoscleral discs, the Descemet's membrane with endothelium had previously been peeled and transplanted during Descemet's membrane endothelial keratoplasty (DMEK). In eight discs, the Bowman's layer had also been separated and transplanted during Bowman's layer transplantation. In all cases, the PDL graft was obtained by corneal pneumodissection. The resulting grafts were preserved for further clinical use.

In all 15 cases, type 1 big bubble with PDL detached from the stroma was successfully created in corneoscleral discs without the Descemet's membrane. In two cases, rupture of the big bubble and damage to the PDL occurred. In 13 cases, the PDL was successfully excised (trephined), stained, and preserved after pneumodissection for subsequent transplantation.

The proposed technique does not require expensive equipment, does not increase the demand for donor tissue, fully complies with the concept of multi-transplantation, and carries a minimal risk of donor tissue rejection.