Allogeneic Tissue Engineering (Nanostructured Artificial Human Cornea) in Patients With Corneal Trophic Ulcers in Advanced Stages, Refractory to Conventional (Ophthalmic) Treatment

Inclusion Criteria: * Man or woman aged≥18, with no upper age limit. * Patients that give their informed consent for study participation. * Stage 3 Mackie corneal ulcers that do not respond to conventional medical treatment, or patients having undergone previous stage 3 Mackie corneal ulcers,33 currently suffering sequelae such as stromal fibrosis or corneal thinning, having no effective therapeutic alternative. * Stromal involvement, not reaching the Descemet membrane. Central or peripheral localization. * Minimum duration of the disease causing the corneal ulcer: 6 weeks. * No active ocular infection. * Patients with normal laboratory parameters as defined by: Leukocytes≥3000 cells/µL; Neutrophils≥1500 cells/µL; Platelets≥100 billion/L; AST/ALT≤1.5 ULN; Creatinine≤1.5 mg/dL. Exclusion Criteria: * Absence of stromal involvement. * Good response to standard medical treatments for corneal disease in less than 3 to 5 weeks. * Bullous keratopathy or other endothelial decompensations. * Active ocular infection. * Positive serology to HBV, HCV, HIV or any other pathology that may interfere with correct patient follow-up. * Pregnant or breast-feeding women or childbearing-age women that do not consent the use of contraceptive methods approved in the protocol. * Medical history of active neoplasia within the past 5 years. Participation in other clinical trials in 3 months previous to inclusion, or in the previous 5 years for trials with advanced therapies.