[1] King Saud Univ, Univ Diabet Ctr, Coll Med, Riyadh 11415, Saudi Arabia
[2] King Saud Univ, Coll Med, Dept Ophthalmol, Riyadh 11415, Saudi Arabia
[3] King Saud Univ, Univ Diabet Ctr, Registry Dept, Riyadh 11415, Saudi Arabia
[4] King Faisal Specialist Hosp & Res Ctr, Dept Biostat Epidemiol & Sci Comp, Riyadh 11211, Saudi Arabia
[5] King Saud Univ, Univ Diabet Ctr, Biostat Dept, Riyadh 11415, Saudi Arabia
[6] King Saud Univ, Univ Diabet Ctr, Clin Dept, Riyadh 11415, Saudi Arabia