Abstract
Purpose: :
A renewed interest in Descemet membrane (DM) has emerged because of research into the pathogenesis of Fuchs corneal dystrophy and the development of procedures that enable the corneal surgeon to replace DM and its attached corneal endothelium by stripping the recipient’s DM and replacing it with posterior donor corneal tissue. In tissue specimens excised from patients who undergo DM stripping automated endothelial keratoplasty (DSAEK) for corneal endothelial decompensation, we observed a unique spine like structure on the anterior surface of DM and carried out a study to learn more about it.
Methods: :
Almost 200 specimens derived from penetrating keratoplasty or DSAEK obtained during the treatment of corneal decompensation were reviewed by light microscopy and sometimes by transmission electron microscopy. To evaluate the anterior surface of DM after it was stripped from the adjacent stroma, corneas obtained postmortem from an eye bank that were rejected for therapeutic use were fixed in glutaraldehyde and prepared for scanning electron microscopy.
Results: :
Aside from the usual morphologic findings of the disorders for which the patients were treated, unique regularly spaced spiny projections were observed in 64% of specimens by light microscopy in portions of DM. They were particularly easy to see in specimens obtained following DSAEK. Spiny structures were not observed by scanning electron microscopy on the anterior surface of DM, but a distinct organized structure was apparent and contained narrow tipped ridges that may coincide with the novel structures evident by light microcopy.
Conclusions: :
A new structural finding on the anterior surface of DM was discovered by light microscopy in specimens obtained mainly by DSAEK. These extracellular configurations resembled spines by light microscopy, but appeared to represent adjacent ridges when examined by scanning electron microscopy in the normal cornea.
Keywords: anatomy • cornea: basic science • pathology: human