Population based outcomes of cataract surgery in three tribal areas of Andhra Pradesh, India: risk factors for poor outcomes. oleh Rohit C Khanna, Srinivasa Reddy Pallerla, Shiva Shankar Eeda, Bala Krishna Gudapati, Sandra D Cassard, Padmaja Kumari Rani, Ghanshyam Palamaner Subash Shantha, Subhabrata Chakrabarti, Oliver D Schein