1. Department of Pediatric Ophthalmology, Medical University of Bialystok, 15-274 Bialystok, Poland.
2. Department of Childhood Diseases, Medical University of Bialystok, 15-274 Bialystok, Poland.
3. Department of Pediatric Laboratory Diagnostic, Medical University of Bialystok, 15-274 Bialystok, Poland.