Myopia and visual acuity impairment: a comparative study of Greek and Bulgarian school children

Abstract

Purpose: To compare the proportions of school children with myopia and impaired visual acuity in Greece and Bulgaria. Methods: A sample of 898 children, aged 10-15 years, was selected from two primary and two secondary schools in a Greek city (Heraklion), and one primary and secondary school in a Bulgarian city (Stara Zagora). Five hundred and eighty eight children were Greek (65.5%, mean age 12.5 ± 0.08 years) and 310 Bulgarian (34.5%, age 12.4 ± 0.07 years). VA was assessed with the habitual refractive correction. Refractive error was measured in the absence of cycloplegia using an auto-refractor. Results:The percentage of children, tested with their habitual refractive correction, with decimal VA <0.5 in at least one eye was 11.7% (95% CI 9.1-14.3%) for Greek and 5.2% (95% CI 2.7-7.6%) for Bulgarian pupils. The percentage of myopic children also differed between the two countries with the proportion with myopic refractive error £)0.75 D and decimal VA <0.8 at primary school level being 14.1% and 28.9% in Stara Zagora and Heraklion respectively and 13.0% and 46.9% (95% CI 18.2-29.2%, p < 0.0001) at secondary school level. Among the myopic pupils only 35.8% used corrective spectacles in Stara Zagora, compared to 70.7% of the children in Heraklion. Finally, myopia appeared more prevalent in female adolescents with the effect being statistically significant only for Greek children (55% vs 40% of males, p = 0.015). Conclusions: The increased proportion of myopic children in Heraklion, compared to Stara Zagora, may arise from a number of environmental and socio-economic factors, which need to be further investigated in order to understand the differences observed among European populations.

Childhood ethnic differences in ametropia and ocular biometry: the Aston Eye Study

“…A refractive error of ≤ −1.50 DS was used to define those ‘likely to be myopic’, with a prevalence of 1.5% in 7‐year‐old white European children. Collectively these findings provide strong evidence that (1) prevalence levels of myopia are markedly higher in older compared to younger British children, in agreement with observations in other European ancestry populations 23–25 , (2) that there are broadly similar levels of myopia in European ancestry children throughout the UK, comparable to levels observed in other white European populations of a similar age 26–28 . However there are differences to children of European ancestry in other parts of the world.…”

“…Collectively these findings provide strong evidence that (1) prevalence levels of myopia are markedly higher in older compared to younger British children, in agreement with observations in other European ancestry populations [23][24][25] , (2) that there are broadly similar levels of myopia in European ancestry children throughout the UK, comparable to levels observed in other white European populations of a similar age. [26][27][28] However there are differences to children of European ancestry in other parts of the world. There is some evidence of lower prevalence of myopia in European ancestry children in Australia whereas those in USA were found to have a higher prevalence of myopia.…”

Worldwide prevalence and risk factors for myopia

“…The prevalence of myopia (SE £ )0.75 D) was 37.2% in Greek children and 13.5% in Bulgarian children. 51 In summary, the prevalence of myopia in Chinese children is higher than other ethnic groups. Moreover, the prevalence of myopia in European children seems to be lower than that in Asian children generally.…”

Rationale, Design, and Demographic Characteristics of the Handan Offspring Myopia Study

“…[5][6][7][8] The rates of myopia in Chinese populations 2,3,9 are much higher than in other populations from Nepal, 10,11 India, 12,13 Africa, 14 Chile, 15 Australia, 16,17 the United States, 18,19 England, 20,21 Greece and Bulgaria, 22 which may also indicate racial susceptibility to myopia. Familial aggregation of myopia has also been studied using family members including twins, [23][24][25] siblings, [26][27][28] and offspring and parents.…”