Corneal avascularity is maintained by soluble vascular endothelial growth factor receptor 1.
Corneal stem cells repopulate the desquamating epithelium. Recent research suggests that corneal stem cells exist in the central cornea as well as at the limbus.
The corneal epithelium provides a barrier to diffusion of hydrophilic molecules; however, corneal proteoglycans confer hydrophilic properties to the stroma. Thus, when hydrophilic drugs are applied topically, the drug molecules must change their biochemical properties to reach the anterior chamber.
Collagen fibrils and fibers (fibril bundles) within the corneal stroma maintain a regular arrangement with minimal variation in diameter. This uniformity is critical for corneal clarity.
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.