[Deep layers of the cornea and basic research in Spain].

An interesting debate (not only in scientific meetings but also in personal conversations) has been taking place amongst ophthalmologists specialized on ocular surface and cornea. A few months ago, 2 articles in the Ophthalmology journal examined the characteristics that could determine the response of corneal tissue to 2 highly “fashionable” surgical techniques: Deep Anterior Lamellar Keratoplasty (DALK) and Descemet Membrane Endothelial Keratoplasty (DMEK). Both articles analyzed at the ultrastructural level (electronic microscope) the characteristics that can determine the success or failure of these procedures which operate on the posterior limits of the corneal stroma as well as on the adjacent Descemet Membrane (DM). It is well known1–3 that collagen fibers account for the physical union between Bowman’s membrane and DM, and that these adhesions are important to maintain them joined to the epithelium as well as the endothelium. However, these 2 papers go beyond that and help us understand the implications for DALK and DMEK of the relationship between the corneal structure and the mechanical properties of the cornea. The research by the Kruse group4 demonstrates that even in the presence of direct insertions of collagen fibers to DM1–3 in cases in which extreme difficulties were encountered to separate DM (a situation which produced tears and tissue loss for use in DMEK), revealed abnormalities at the ultrastructural level (“tweezer-type” connections) as well as at the