Prevalence, progression and associations of corrected refractive errors: a cross-sectional study among students of a Medical College of Odisha, India

Abstract

Background: WHO estimates that Refractive errors are a major cause of blindness in the world leading to 42% cases of visual impairment. Refractive errors are a significant issue among young adults; this study was conducted to find out the prevalence, progression and associations of refractive errors in medical students. Methods: This was a cross-sectional study conducted among all the students of MKCG Medical College, Berhampur, Odisha, India. Results: Out of the 506 subjects analysed, 47.4% used spectacles and 2.2% used contact lens. 48.8% of spectacle users and 81.8% of contact lens users were females and the rest males. The mean age of the sample was 22.52 years (SD=1.90). The mean age at which refractive error was diagnosed is 16.47 (SD=3.42) and the duration of corrected refractive errors was 5.90 years (SD=3.90). The most common refractive error prevalent was Myopia (54.5%) followed by combined myopia and astigmatism (31.3%), hypermetropia (8.6%) and astigmatism (5.6%). The corrected refractive error ranged from 0.25 to -12.5 D for Myopics and 0.25 to -2.5 D for Hypermetropia with a median correction of -1.75 D spherical, 0.00 D cylindrical in the right eye and the left eye alike. 73.3% of the subjects reported an increase in refractive errors since diagnosis. There was a significant increase in refractive error in myopia as compared to hypermetropia (χ2=5.20, p=0.023) and no difference between males and females (p=0.91). 26.7% respondents reported selective use of spectacles and 62.5% used bright light for reading purposes. Their most preferred activity during leisure time was mobile phone use (43.8%) followed by laptop/pc use (16.3%). 90% had at least 1 ophthalmological check up in the last 12 months. Significant difference was found among those with and without refractive errors in their Height (p=0.026), time spent reading per day (p=0.001). Significant positive correlation was reported between duration of spectacle use and the increase in dioptre power (r=0.32, p<0.01 for spherical and r= 0.24, p<0.01 for cylindrical). No significant difference was found among the same regarding patterns of TV / PC/ Mobile phone use, sleep duration, age and weight of the respondents. Conclusions: The high prevalence of spectacle use warrants further studies for establishing the pattern of change in refractive errors and behavioural habits.