Epidemiologic study of myopia in a population of schoolchildren in Tunisia.

BACKGROUND: Uncorrected refractive error has recently been identified as the leading cause of visual impairment in children worldwide. The prevalence of myopia is increasing. Determination of the epidemiology of myopia is important to develop screening strategy. PURPOSE: to estimate the prevalence and the degree of severity of myopia among primary schoolchildren in Tunisia and to assess its effect on school performance. METHODS: A random cluster design was used to recruit children from primary schools across urban and rural settings in Tunisia, during 2009 to 2012. A total of 6192 students aged 6 to 14 years old were enrolled. Students with visual acuity of 9/10 or worse underwent a complete ophthalmic examination, and cycloplegic autorefraction was used to determine refractive error. Myopia was defined as a spherical equivalent (SE) of - 0.50 dioptre (D) or worse. We also searched for a possible relation between uncorrected myopia and academic failure. RESULTS: The prevalence of myopia was 3.71%. Mean and SD of spherical equivalent was -3,10 ± 0,86 D. The myopia rate increased significantly with age (p=0.04), but was not significantly related to gender (p=0.823). There was no significant association between the student's area of residence and myopia (p=0.932). 85.21% of myopic students experienced unsatisfactory academic performances. CONCLUSION: The present study reveals the prevalence of myopia among schoolchildren in Tunisia. The high rate of academic failure in myopic schoolchildren emphasizes an unmet need for its screening and its correction.

Characteristics of Astigmatism in a Population of Tunisian School-Children.

PURPOSE: To evaluate the characteristics of astigmatism in a cross-sectional study of schoolchildren in Tunisia. MATERIALS AND METHODS: A random cluster design was used to recruit children from primary schools across urban and rural settings in Tunisia, from 2008 to 2010. A total of 6192 students aged 6-14-years old were enrolled. All students whose uncorrected visual acuity was worse than 20/20 underwent a complete ophthalmic examination. Astigmatism was defined as the cylinder power of 0.75 diopter (D) or greater. RESULTS: The prevalence of astigmatism was 6.67%. Mean cylinder power was - 1.89 ± 0.79D. The prevalence of astigmatism increased statistically significantly with age (P = 0.032). The prevalence of astigmatism was not significantly related to gender (P = 0.051). Of those with cylinder, 63.6%, 17.8%, and 18.6% schoolchildren had with with-the-rule, against-the-rule, and oblique astigmatism, respectively. ATR astigmatism was significantly higher in males (P = 0.033). There was no significant association between the student's area of residence and astigmatism (P = 0.059). CONCLUSION: Comparisons with other studies show that the prevalence of astigmatism in Tunisia is higher than in some countries. The prevalence of astigmatism increased with age but not gender. The majority of schoolchildren had with-the-rule astigmatism.