Beneath the basal lamina of the epithelium is the Bowman layer, or Bowman membrane, a tough layer consisting of randomly dispersed collagen fibrils. It is a modified region of the anterior stroma that is 8–15 μm thick (see Fig 2-2). Unlike the Descemet membrane, it is not restored after injury but is replaced by scar tissue.
A, The corneal epithelium is composed of 4–6 cell layers that make up a stratified squamous epithelium, which is derived from the surface ectoderm. B, Schematic of the corneal epithelium demonstrating adhesion between cells and to the underlying basal lamina (purple) and Bowman layer via hemidesmosomes. B = basal cells; S = surface cells; W = wing cells.
(Reproduced with permission from Levin LA, Nilsson SFE, Ver Hoeve J, Wu SM. Adler’s Physiology of the Eye. 11th ed. Philadelphia: Elsevier/Saunders; 2011:94.)
Excerpted from BCSC 2020-2021 series: Section 2 - Fundamentals and Principles of Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.