Distribution of near Point of Convergence, near Point of Accommodation, Accommodative Facility and Refractive Errors in a Rural Population Living in Northern Iran.

Purpose: To evaluate near point of convergence (NPC), near point of accommodation (NPA), and accommodative facility (AF) in order to determine their normative data in a rural population.

Methods

The target population for this population-based, cross-sectional study was people living in rural areas. Each subject underwent extensive optometric and ophthalmic examinations, including the measurement of visual acuity, refraction, NPA, NPC, and AF.

Results

The data of 1113 individuals was analyzed of whom 58.8% (n = 576) were women. The mean age of the participants was 15.26 ± 7.38 years (range: 6-30 years). The mean spherical equivalent of the subjects was 0.16 ± 0.63 D. The prevalence of myopia, hyperopia and astigmatism was 16.28% (13.97-18.58), 5.97% (4.49-7.44), 11.93% (9.91-13.95) in this study, respectively The mean and 95% confidence interval of NPC, NPA, and binocular accommodative facility (BAF) was 6.99 cm (6.84-7.15), 9.91 cm (9.71-10.11), and 9.84 cpm (9.63-10.06), respectively. A significant correlation was found between age and the parameters such that all evaluated parameters worsened significantly with age (P < .001).

Conclusion

The results of the present study showed the normal ranges of NPA, NPC, and BAF in a 6-30 year-old population living in rural areas of northern Iran. These parameters changed significantly with age.