[1] Univ Toronto, Int Dev, Toronto, ON, Canada
[2] Kenyatta Natl Hosp, Nairobi, Kenya
[3] Univ Nairobi, Dept Ophthalmol, Nairobi, Kenya
[4] Univ Toronto, Fac Med, Dept Ophthalmol & Vis Sci, Toronto, ON, Canada
[5] Univ Toronto, Dalla Lana Sch Publ Hlth, Div Clin Publ Hlth, Toronto, ON, Canada
[6] Hosp Sick Children, Dept Ophthalmol & Vis Sci, 555 Univ Ave, Toronto, ON M5G1X8, Canada
[7] SickKids Res Inst, Child Hlth Evaluat Sci Program, Toronto, ON, Canada
[8] SickKids Res Inst, Ctr Global Child Hlth, Toronto, ON, Canada