1. Ophthalmology Clinic, Clinical Center Niš, Bulevar dr Zorana Đinđića 48, 18000 Niš, Serbia
2. Department of Ophthalmology, Faculty of Medicine, University of Niš, Bulevar dr Zorana Đinđića 81, 18000 Niš, Serbia
3. Community Health Center Niš in Niš, Vojvode Tankosića 15, 18000 Niš, Serbia
4. Special Hospital for Ophthalmology “Clinic Maja”, Vizantijski Bulevar 8, 18000 Nis, Serbia
5. Department of Clinical and Experimental Surgery, Faculty of Medical Sciences, University of Kragujevac, Svetozara Markovića 69, 34000 Kragujevac, Serbia
6. Eye Clinic, Clinical Center Vojvodina, Hajduk Veljkova 1-9, 21000 Novi Sad, Serbia
7. Department of Ophthalmology, University of Medicine and Pharmacy “Victor Babes”, Piata Eftimie Murgu, No. 2, 300041 Timisoara, Romania