Abstract
Purpose: :
The purpose of this study was to investigate the prevalence of accommodative infacility in a population of Swedish adults aged between 18-41 years and to assess whether there is any relationship between amount of near work, symptoms and accommodative facility measurements.
Methods: :
Eighty subjects (mean age ± SD = 27.6 ± 6.8 years) living in southern part of Sweden were recruited for this study. All the subjects had normal accommodative amplitude (> 5 D) and Stereopsis. Accommodative facility was measured binocularly at 40 cm with ± 2.00 D and ± 1.00 D flippers and the number of cycles cleared for one minute period (cycles per minute-cpm) was documented. All the subjects completed a questionnaire providing information about the number of hours of near work performed in a week and also any symptoms related to accommodative infacility.
Results: :
A paired samples t-test was performed to compare the accommodative facility values between the ±1.00 D and ±2.00 D measurements. The analysis showed a significant difference (p < 0.001) between them. The mean binocular accommodative facility with ± 2.00 D flippers was 8.72 ± 4.44 cpm and with ± 1.00 D was 16.38 ± 4.61 cpm. The prevalence of accommodative infacility with ±2.00 D flippers (less than one SD below mean, 0 to 4 cpm in this sample) was 18.75%. There was a significant difference in facility values between symptomatic and asymptomatic groups with ± 2.00 D flippers (p<0.05). The mean amount of near work was 35.02 ± 15.35 hours per week. There was no significant correlation between the amount of near work and accommodative facility (r = 0.048, p > 0.05).
Conclusions: :
The prevalence of binocular accommodative infacility in this sample was 18.75%, which is slightly higher than previous studies. There was a significant difference in the facility values between symptomatic and asymptomatic groups. This study adds new prevalence data to the field of binocular vision from Swedish population.
Keywords: accommodation • binocular vision/stereopsis • clinical (human) or epidemiologic studies: prevalence/incidence