1. Department of Medicine, Surgery, and Pharmacy, University of Sassari, 07100 Sassari, Italy
2. Ophthalmology Unit, Azienda Ospedaliero Universitaria di Sassari, 07100 Sassari, Italy
3. Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy
4. Department of Ophthalmology, University of Turin, 10126 Turin, Italy
5. Ophthalmology Unit, Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
6. Ophthalmology Unit, Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, Italy