Open-label Prospective Clinical Trial Evaluating the Safety and Efficacy of Biosynthetic CLP-PEG-MPC Corneal Implants in Patients Undergoing High-risk Deep Anterior Lamellar Keratoplasty.

Inclusion Criteria: 1. adult age (18 years or older at the time of subject eligibility visit) 2. able to provide signed, informed consent 3. unilateral corneal opacity not involving the posterior corneal layers (Descemet membrane and endothelium) for which DALK is indicated 4. visual acuity less than 20/200 in the affected eye and better than 20/50 in the contralateral eye (i.e. monocular blindness) 5. presence of at least one of the following high-risk criteria for corneal transplantation using a human cornea donor graft: 5i) inflammation 5ii) active infection 5iii) stromal neovascularization 5iv) neurotrophism 5v) autoimmune disease 5vi) previous DALK graft failure 6. availability for 24 months of postoperative follow-up Exclusion Criteria: 1. Age under 18 years 2. Inability to give informed consent 3. Previous corneal perforation precluding DALK surgery 4. Endothelial pathology requiring penetrating keratoplasty 5. Limbal stem cell deficiency affection more than 50% of the limbus 6. Previous penetrating or endothelial keratoplasty 7. Bilateral blindness 8. Nystagmus 9. Uncontrolled glaucoma or intraocular pressure 10. Documented macular disease (age-relate macular degeneration, macula-involving retinal detachment, macular hole) 11. Documented amblyopia of surgical eye