[1] Aristotle Univ Thessaloniki, Sch Med, Dept Ophthalmol 2, Thessaloniki 56429, Greece
[2] Aristotle Univ Thessaloniki, Sch Med, Dept Hyg & Epidemiol, Thessaloniki 56429, Greece
[3] King Khalid Eye Specialist Hosp, Div Pediat Ophthalmol, Riyadh, Saudi Arabia
[4] North Shore Univ Hlth Syst, Dept Surg, Evanston, IL USA
[5] Univ Chicago, Pritzker Sch Med, Dept Surg, Chicago, IL 60637 USA
[6] Retina Fdn Southwest, Crystal Char Ball Pediat Vis Evaluat Ctr, Dallas, TX USA
[7] Pediat Ophthalmol & Adult Strabismus, Plano, TX USA
[8] Great Ormond St Hosp Sick Children, Clin & Acad Dept Ophthalmol, London, England
[9] Western Eye Hosp, London, England
[10] Santa Clara Valley Med Ctr, Dept Surg, Div Ophthalmol, San Jose, CA 95128 USA
[11] Univ Calgary, Alberta Childrens Hosp, Dept Surg, Vis Clin, Calgary, AB, Canada
[12] Emory Univ, Sch Med, Dept Ophthalmol, Atlanta, GA USA
[13] Univ Sydney, Sydney Eye Hosp Campus, Sydney Med Sch, Save Sight Inst,Discipline Ophthalmol, Sydney, NSW 2006, Australia
[14] UPMC, Childrens Hosp Pittsburgh, Ctr Eye, Pittsburgh, PA USA