1. Department of General Ophthalmology, Medical University in Lublin, Lublin, Poland
2. Department of Ophthalmology, Rostock University Medical Center, Rostock, Germany
3. Institute for Biostatistics and Informatics in Medicine and Ageing Research, Rostock University Medical Center, Rostock, Germany
4. Department of Ophthalmology, Tufts University Boston, MA, U.S.A.
5. Department of Ophthalmology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany