Myopia and visual acuity impairment: a comparative study of Greek and Bulgarian school children.
OBJECTIVE
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 <or=-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.
Plainis
Sotiris
S
Institute of Vision and Optics (IVO), School of Health Sciences, University of Crete, PO Box 2208, 71003 Heraklion, Crete. plainis@med.uoc.gr
Moschandreas
Joanna
J
Nikolitsa
Panagoula
P
Plevridi
Eleani
E
Giannakopoulou
Trisevgeni
T
Vitanova
Vania
V
Tzatzala
Paraskevi
P
Pallikaris
Ioannis G
IG
Tsilimbaris
Miltiadis K
MK
D000293:Adolescent; D000367:Age Factors; D001251:Astigmatism / Q000453:epidemiology / Q000503:physiopathology*; D002031:Bulgaria / Q000453:epidemiology; D002648:Child; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D008297:Male; D009216:Myopia / Q000453:epidemiology / Q000503:physiopathology*; D013223:Statistics as Topic; D014786:Vision Disorders / Q000453:epidemiology / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*