[1] Assiut Univ, Dept Ophthalmol, Fac Med, Assiut, Egypt
[2] Univ Ottawa, Dept Ophthalmol, Ottawa, ON, Canada
[3] Univ Arkansas Med Sci, Jones Eye Inst, Little Rock, AR 72205 USA
[4] Jackson Lab, Farmington, CT USA
[5] Univ Arkansas Med Sci, Coll Med, Coll Publ Hlth & Biomed Informat, Epidemiol Dept, Little Rock, AR 72205 USA
[6] Univ Bristol, Sch Clin Sci, Bristol, Avon, England
[7] Bristol Eye Hosp, Bristol, Avon, England
[8] Royal Wolverhampton Hosp NHS Trust, Wolverhampton Eye Infirm, Wolverhampton, W Midlands, England
[9] Gloucestershire Hosp NHS Trust, Ophthalmol Dept, Cheltenham, Glos, England