Figure 1. Schematic diagram of the preparation of corneal equivalent made with collagen. Cells were harvested from human corneas and separately grown in culture dishes. Just before confluence, cells were trypsinized to produce a suspension. Cells were added over the collagen construct cast in a Petri dish (model 1). Alternatively, endothelial cells obtained from bovine corneas were seeded over a culture insert to produce a collagen corneal construct made of human epithelium and keratocytes (model 2).