“…The remaining 73 population-based studies provided information on a total of 384 658 subjects (194 944 males and 189 664 females; strabismus cases: 4980 males and 4890 females). Partially overlapping with these reports, 42 studies provided gender information about esotropia (cases: 1979 males and 1911 females), and 43 studies provided gender information on exotropia (cases: 1477 males and 1447 females) [ 10 , 14 - 16 , 22 , 32 - 35 , 37 , 41 , 43 , 44 , 46 - 54 , 57 , 61 , 62 , 64 , 65 , 67 , 69 - 71 , 74 , 77 - 79 , 82 , 84 , 85 , 90 - 93 ]. The global distribution of the 73 population-based studies reporting on horizontal strabismus is shown, along with their cohort sizes, in Figure 2 , panel A.…”