A new biomaterial made from human placental collagen type IV has been developed in corneal inlays for refractive keratoplasty. Eight dogs received intracorneal lenses to investigate biocompatibility. Postoperative follow-up observation of 2 years revealed that the eyes remained clear and without inflammatory reaction. Endothelial cells were unaltered. Histological and ultrastructural studies showed no signs of inflammation, ulceration, or encapsulation. No fibroblastic activity was evident at the lens stroma interface.