Role of ACE and PAI-1 Polymorphisms in the Development and Progression of Diabetic Retinopathy. oleh Saba Saleem, Aisha Azam, Sundus Ijaz Maqsood, Irfan Muslim, Shaheena Bashir, Nosheen Fazal, Moeen Riaz, Syeda Hafiza Benish Ali, Muhammad Khizar Niazi, Mazhar Ishaq, Nadia Khalida Waheed, Raheel Qamar, Maleeha Azam