Prevalence of general binocular dysfunctions among rural schoolchildren in South Korea

BACKGROUND/PURPOSE: To assess the prevalence of nonstrabismic accommodative and vergence dysfunctions among primary schoolchildren in Hampyeong, a rural area of South Korea. METHODS: Five hundred and eighty-nine primary schoolchildren, 8-13 years old, were each given a thorough eye examination, including binocular-vision testing, near point of convergence, horizontal phoria measurement by von Graefe, and negative and positive vergence amplitudes with prism bar, to determine any form of accommodative or vergence dysfunctions. RESULTS: Of the 589 participants examined, 168 (28.5%) primary schoolchildren presented some form of nonstrabismic accommodative or vergence dysfunctions. The prevalence of accommodative dysfunctions and vergence dysfunctions was 13.2% and 9%, respectively. Convergence insufficiency (10.3%) was more prevalent than convergence excess (1.9%), and accommodative insufficiency (5.3%) was more prevalent than accommodative excess (1.2%). CONCLUSION: This study suggests that nonstrabismic accommodative and vergence dysfunctions are prevalent in the rural area of South Korean primary schoolchildren, and convergence insufficiency was the most prevalent.