Posterior corneal anatomy in a newborn baby

Abstract

PurposeIn view of the recent developments in our understanding of posterior corneal anatomy and the description of a unique layer and zone in adults, we investigated two corneas from a three‐week‐old baby.Methodsboth corneas were subjected to intra stromal air injection using a 30G needle. The type of big bubble formed was identified. The wall of the big bubble and the posterior stromal interface with Descemet membrane was studied using light microscopy, electron microscopy and immune‐histological studies.ResultsIntra stromal injection of air resulted in the formation of characteristic type 1 big bubble in one cornea and another characteristic type II big bubble in another. The wall of the type I big bubble bubble was made of endothelial cells, Descemet's membrane and a thin collagen layer anteriorly (previously described as Dua's layer [DL]).DL was made of 7‐8 collagen lamellae of compactly opposed collagen. This was made of predominantly type I collagen with abundance of collagen VI. Thrombospondin was characteristically seen along the posterior surface of DL extending to the trabecular meshwork. The interface between DL and DM was not distinct but presented a transition zone. The wall type II big bubble was made of Descemet membrane only, which was extremely thin.ConclusionsWe demonstrated here that the human infant cornea behaves similarly to adult cornea when subjected to air injection (dissection). We also demonstrated the presence of DL in a 3 week old baby and presented its histological characteristics.