1. Department of Ophthalmology with Pediatric Unit, St. Barbara Hospital, Trauma Center, Medykow Square 1, 41-200 Sosnowiec, Poland
2. Department of Ophthalmology, District Railway Hospital, Panewnicka 65 St., 40-760 Katowice, Poland
3. Chair and Clinical Department of Ophthalmology, School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia in Katowice, Panewnicka 65 St., 40-760 Katowice, Poland
4. Hebei Provincial Eye Hospital, Xingtai, China