Abstract
Purpose: :
To report a novel enzymatic technique that facilitates air separation of Decemet’s membrane from deep corneal stroma.
Methods: :
Fresh human corneoscleral tissue, preserved in Optisol and not suitable for transplantation, was obtained from the Mississippi Lions Eyebank. The corneoscleral tissue was mounted on a custom made holder. In a control group, air was injected into the stroma. A second group received an stromal injection of 2 mg/ml Collagenase A in BSS that was left in the stroma for 1 hour. A third group received an injection of 2 mg/ml Collagenase A in BSS into the stroma followed by an injection of air 1 hour after injecting Collagenase A. All injections were performed using a 27G needle into the deep stroma without penetrating Descemet’s membrane. Histological examination and electron microscopy of the cleavage plane between the stroma and the Descemet’s membrane were performed.
Results: :
Injection of air or collagenase into the deep corneal stroma did not result in a reproducible separation of the stroma/Descemet's junction. In contrast, deep stroma and Descemet's membrane were easily and reproducibly separated using a combination of Collagenase and air injection. The separation was confirmed using Visante OCT, light microscopy and electron microscopy. The cleavage plane seems to be located between the junction of the posterior stroma and the anterior banded layer of Descemet's membrane.
Conclusions: :
This novel enzymatic technique facilitates the separation of Descemet’s membrane from the stroma. Future applications include harvesting of Descemet’s membrane for endothelial transplantation and may be considered as an adjuvant for the Big-Bubble technique.
Keywords: cornea: stroma and keratocytes • cornea: endothelium • enzymes/enzyme inhibitors