Prevalence of amblyopia and refractive errors in an unscreened population of children

Purpose: 

To describe the frequency of refractive errors and amblyopia in unscreened children aged 2 months to 12 years from a rural town in Poland. 

Methods:

Five hundred ninety-one children were identified by medical records and examined in a standardized manner. Visual acuity was measured using LogMAR charts; refractive error was determined using retinoscopy or autorefraction after cycloplegia. Myopia was defined as spherical equivalent (SE) ej0.50 D, emmetropia as SE between j0.5 D and +0.5 D, mild hyperopia as SE between +0.5 D and +2.0 D, and high hyperopia as SE Q+2.0 D. Amblyopia was classified as best-corrected visual acuity Q0.3 (e20/40) LogMAR, in combination with a 2 LogMAR line difference between the two eyes and the presence of an amblyogenic factor. 

Results:

Refractive errors ranged from 84.2% in children aged up to 2 years to 75.5% in those aged 10 to 12 years. Refractive error showed a myopic shift with age; myopia prevalence increased from 2.2% in those aged 6 to 7 years to 6.3% in those aged 10 to 12 years. Of the examined children, 77 (16.3%) had refractive errors, with visual loss; of these, 60 (78%) did not use corrections. The prevalence of amblyopia was 3.1%, and refractive error attributed to the amblyopia in 9 of 13 (69%) children. 

Conclusions: 

Refractive errors are common in Caucasian children and often remain undiagnosed. The prevalence of amblyopia was three times higher in this unscreened population compared with screened populations. Greater awareness of these common treatable visual conditions in children is warranted.