1. Ophthalmology, Medical University of Sofia, Sofia, Bulgaria
2. Department of Ophthalmology, University Hospital Bern, Bern, Switzerland
3. Division of Human Genetics, Department of Pediatrics, Inselspital University Hospital Bern, Bern, Switzerland
4. Department of Ophthalmology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland
5. Department of Ophthalmology, University of Zurich, Zurich, Switzerland
6. Department of Ophthalmology, University Hospital Basel, Basel, Switzerland