1. Ophthalmology Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
2. Dermatology Unit, Department of Medical, Surgical and Neurosciences, University of Siena, Siena, Italy
3. Department of mathematics and informatics, University of Catania, Catania, Italy
4. Department of Ophthalmology, University of Catania, Catania, Italy
5. Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Napoli, Italy