The prevalence of reduced visual acuity in children from an urban district in China from 2002 to 2018

Abstract

Background: To investigate trends in the prevalence of reduced visual acuity (VA), a proxy measure for myopia, in an urban district in China.

Methods: Data were extracted from the dataset of the 2002 and 2018 Annual Survey on Students' Constitution and Health from Yuhua District, Changsha City, China. Children aged 6-15 years were included in the study. VA was measured using a LogMAR tumbling E chart. The prevalence of reduced VA was calculated by age and gender. The chi-square test was used to compare the differences between groups.

Results: The final VA analysis included 26217 children in 2002 and 45510 children in 2018. The overall prevalence of reduced VA increased from 28.3% in 2002 to 46.5% in 2018 (P < 0.001). The prevalence of reduced VA started to increase markedly from the age of 14 years in 2002, while in 2018 it started to increase markedly from the age of 9 years. The prevalence of severely reduced VA increased in all age groups from 2002 to 2018 and increased with age (all P < 0.001). In 2002, over 50% of children in all age groups had normal VA. By 2018, the prevalence of normal VA decreased from 61.4% in those aged 6 years to 31.9% in those aged 15 years.

Conclusions: The prevalence of reduced VA among children aged 6-15 years in Yuhua District has become more common with age, and there has been a marked increase in the prevalence of reduced VA from 2002 to 2018. The remarkable epidemic of reduced VA started 5 years earlier in 2018 than in 2002. Evidence from the present study suggests that interventions should be launched before the age of 9 years.