[On the issue of separate designation of the pre-Descemet's layer in the structure of the cornea].

The five-layer structure of the cornea has been generally accepted in anatomy for the last 70 years. Since the beginning of 2000, publications about lamellar keratoplasty have appeared, in which during the operation it was necessary to isolate the Descemet's membrane (DM). Several options for the formation of a big bubble have been described; in the most frequently used type, the presence of remnants of thin stromal tissue on the isolated DM were found. In 2013 an English group of researchers headed by H. Dua tried to prove that this thin strip of the stroma in DM is the sixth layer of the cornea. However, there is a sufficient number of publications that refute this "discovery". In Russian scientific literature there has been no discussion of a «new» layer of the cornea. Only recently one article has been published, which raised the issue of this separate layer in the cornea. Our group of authors has also entered this discourse, believing that it is possible to distinguish terminologically the pre-Descemet's layers, but only as part of the corneal stroma, without attributing it with numerous functions and features.