Between which structures lies Descemet's membrane?

• A. Posterior corneal stroma and endothelial cells
• B. Anterior corneal epithelium and stroma
• C. Iris and lens
• D. Conjunctiva and sclera

Answer: (A)

Descemet's membrane is the basement membrane of the corneal endothelium, forming the inner boundary of the cornea. It lies right between the posterior stroma and the endothelial cell layer, facing the aqueous humor. This placement comes from it being produced by the endothelium itself, serving as its basement membrane and separating the endothelium from the thick stroma behind it. It’s not located between the anterior epithelium and stroma (that would be Bowman's layer), nor is it near the iris, lens, conjunctiva, or sclera. So the correct location is between the posterior corneal stroma and the endothelial cells.