1. Ophthalmology Clinic, Department of Medicine and Science of Ageing, University “G. d’Annunzio” of Chieti-Pescara, Via dei Vestini 31, 66100 Chieti, Italy
2. Eye Clinic, Department of Medical Science, Neuroscience and Sense Organs, University of Bari, 70121 Bari, Italy
3. International Agency of Prevention of Blindness, 00185 Rome, Italy
4. Laboratory of Biostatistics, Department of Medical, Oral and Biotechnological Sciences, University “G. d’Annunzio” of Chieti-Pescara, Via dei Vestini 31, 66100 Chieti, Italy