When do patients need corneal transplants?
D002387:Cataract Extraction; D003315:Cornea / Q000098:blood supply; D003317:Corneal Dystrophies, Hereditary / Q000601:surgery; D065306:Corneal Injuries; D003318:Corneal Opacity / Q000601:surgery; D016039:Corneal Transplantation; D003320:Corneal Ulcer / Q000601:surgery; D005128:Eye Diseases / Q000601:surgery*; D006801:Humans; D013518:Surgery, Plastic; D014184:Transplantation, Homologous; D014792:Visual Acuity