Abstract
Purpose :
Recently, the junction between Descemet’s membrane and the corneal stroma has been designated by some authors as a novel hitherto not recognized anatomical layer in the adult cornea. This has been under extensive debate since further detailed investigations by others could not find characteristics required to define a new structure. We therefore looked at the area under discussion in fetal eyes to see whether there is any evidence for the formation of such a specific anatomical feature.
Methods :
We evaluated eight Karnovsky-fixed Epon-embedded fetal eyes (12 to 22 WoG). Two newborn corneas and two adult corneas (54 and 78 years) were retrieved from eyes fixed in paraformaldehyde. Semithin sections were obtained from the central cornea as well as (if possible) from the periphery, followed by ultrathin sections of the respective area including Descemet’s membrane and the posterior cornea.
Results :
Our morphologic findings were in concordance with previously described features of the developing Descemet’s membrane. At the time points available for our study, a regular collagen arrangement with an increasing number of basal lamina lamellae between the endothelium and the stroma, corresponding to increasing age, was observed. No particular adhesion structures nor morphologically different collagen features were noted, and cellular elements were found in variable distance. Similarly, at the border towards the trabecular meshwork, there appeared to be an increase in elastic fibers (particularly in the older specimens) and in cellular elements without an obvious stratum extending from Descemet’s into the trabecular meshwork. Thus, no additional specific pre-Descemet layer was evident neither in the central cornea nor at the junction with the trabecular meshwork.
Conclusions :
Our morphologic study could not confirm the proposed development of an additional particular anatomical structure between Descemet’s membrane and the corneal stroma. Obviously, biochemical and immunochemical analyses of the intercollagenous matrix would help in further defining this particular interface attaching the posterior stromal lamellae and the trabecular beams to Descemet’s membrane.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.