The review of refractive studies of nonadults in Poland.

Abstract

Epidemiology trends are based on data coming from different countries, and sometimes local studies are not easily available. Thus, we decided to collect and analyse the results of the major refractive studies from Poland related to nonadults. We selected published and unpublished studies on refractive errors, performed in recent twenty years in Poland, which comprised at least 1000 randomly selected subjects. PubMed database and doctoral theses database in Poland were surveyed in years 1997–2017. Based on these criteria, three studies on refractive errors have been found. Although, in all those studies, the samplings included all grades of school, and the distribution of refractive errors by age was available from two studies. The definitions of myopia, hyperopia and astigmatism are presented in Table 1 and differ between those studies. Dalz examined 4440 schoolchildren from the city of Poznan, 2427 girls and 2013 boys, aged 7–18 years. Autorefraction measurements were conducted after cycloplegia induced with 1% tropicamide. In whole group, the prevalence of myopia was 11.4% and increased from 0.4% in children aged 7 years to 22.0% in students aged 18 years. The prevalence of hyperopia decreased from 32.6% in children aged 7 years to 10.6% in students aged 18 years. (Dalz 2003) Czepita et al. reported the results of the refractive study in 4442 schoolchildren from the urban and semirural area of Szczecin, 2315 girls and 2107 boys, aged 6–18 years. The ophthalmic examination included retinoscopy after cycloplegia induced with 1% tropicamide. This study showed that prevalence of myopia was 13.1% and increased from 2.0% in children aged 6 years to 32.6% in students aged 18 years. The prevalence of hyperopia decreased from 36.5% in children aged 6 years to 3.2% in students aged 18 years. (Czepita et al. 2007) In both studies, significant increase in the prevalence of myopia was observed: between ages fourteen and fifteen in Dalz's study and between ages fifteen and sixteen in Czepita's study. The authors suggested that this was mainly attributable to the faster adolescence and increased amount of near work related to the intensive education of the children in higher levels of school. In Poland, all children from elementary school ought to continue to secondary school because of learning duty up to the age of sixteen. However, we cannot exclude the sampling bias as in Dalz study an oversampling of children aged fifteen years has been found. Finally, Szaflik et al. published the results of the refractive study in 1002 schoolchildren from the cities of Warsaw, Pultusk and Walbrzych. There were 505 girls and 497 boys, aged 6–16 years. Myopia was defined as spherical equivalent (SE) ≤ −0.5 dioptres (D), hyperopia as SE ≥ +0.5 D, and astigmatism was considered if the cylinder was ≥0.5 D. It was observed that 16.9% of children were myopic, while 19.9% were hyperopic. Various forms of astigmatism were found in 29.9% of children. (Szaflik et al. 2004). In all reported studies in children, the prevalence of myopia increased and simultaneously the prevalence of hyperopia decreased with increasing age. The distribution of refractive errors varied in different populations of Polish children. It was mainly attributable to the differences in the study design, that is, different definitions of refractive errors and different age range in sampled children. All selected studies comprised children from the urban areas. However, the study by Czepita et al. also comprised children from the semirural areas. The prevalence of myopic refractive error found in these urban populations of Polish children was similar to those reported in western Europe, America and Africa but differed from urban Asian populations. (Pan et al. 2012). In conclusion, among Polish children, the prevalence of myopia increased, while the prevalence of hyperopia decreased with increasing age. The rate of myopia found in Polish children is comparable with other white Caucasians populations.