DISTRIBUTION OF NEAR LATERAL PHORIA AMONG SCHOOL AGE CHILDREN (6-15 years)

ABSTRACT

Heterophoria is a latent deviation of the visual axis of the eye manifested in the absence of fusion. Comfortable reading and the performance of near activities involves efficient accommodative and vergence systems. However, accommodative and vergence anomalies are associated with various symptoms that impair efficient visual performance in school age school. The purpose of this study was to determine the distribution of near lateral phoria among school age children within the age bracket of (6-15 years). Near lateral phoria was measured on a sample of 140 school age children in the University of Benin staff school and University demonstration secondary school using maddox rod and prism bars. The measurement for the test per participant were obtained and afterward data obtained were analysed. The distribution of exophoria for this school age children ranged from 1pd exophoria to 8pd exophoria with a mean of 2.89 ± 1.68Δ, and esophoria had a range from 1pd esophoria to 8pd esophoria with a mean of 2.79 ± 1.45Δ. The Unpaired T-test was carried out to determine if there was significant difference between variables. Statistical analysis revealed no significant difference in near lateral phoria with gender variation, P=0.680, (P>0.05). This suggests that gender may not be a significant factor influencing near phoria in this cohort. It was concluded that in the distribution of near lateral phoria among this school age children, exophoria had a prevalence of 54.3% and esophoria had 44.3%. Notable proportion of the participants displayed 2Δ exophoria and 2Δ esophoria and gender differences did not emerge as significant factors influencing near phoria within this cohort.