Determinants of the progress of myopia among Omani school children: a historical cohort study

This study was conducted in 2002-2003 at selected schools of eight health regions of Oman. The authors present risk factors and predictors of progression of myopia between the 7th and 10th grades.

This was a historical cohort study. A total of 1304 students in 10th grade, both with and without progression of myopia, were examined by the refractionists. Vision, refraction, and physical measurements of each student were recorded. The health records of all students were reviewed to note the same parameters measured when they were in 7th grade. The odds of progression in height, progression in weight, protein energy malnutrition status, sex, age, history of refractive error in parents and sibling, evidence of trachoma, and allergic conjunctivitis were calculated to associate them to the progression of myopia.

Mean progression of myopia was 0.37 D per year (SD = 0.27D). The mean progression of myopia among students with history of myopia in 7th grade was 0.21 D more than that of students not having myopia in 7th grade (95% CI 0.12-0.29). Multivariate regression analysis suggested that weight of student in the 7th grade (t=-2.2, p=0.031), positive history of myopia in one of the siblings (t=2.44, p=0.015), and myopia in the 7th grade (t=4.56, p<0.001) were associated with the progression of myopia.

Family history of myopia and myopia at younger age were predictors for progressive myopia in teenaged Omani children. However, the role of body mass index at a younger age to predict progressive myopia was not conclusive.