There are many causes of sudden onselt of blindness. Given the medical history, it is entirely possible that blockage of blood vessels can cause this as well. I would recommend that you seek the care of an eyeMD to determine the cause and treatment.
Sandy T. Feldman, M.D., M.S.
ClearView Eye and Laser Medical Center
San Diego, California
Giant Cell cause sudden blindness. The artery dries up going to the eye, Prednisone is taken to prevent this. I have Giant Cell.