Study of Risk Factors Associated with Myopia in Medical Students: A Case-Control Study
Background: Myopia has emerged as a serious vision-threatening disease globally. Due to its increasing prevalence in the last few decades, it is now considered that along with genetics, environmental and lifestyle factors are also playing some role in the development of myopia. Thus, this study was planned to evaluate the effects of various risk factors in the development and progression of myopia by comparing them with people without myopia.
Materials and Methods: A case-control study was conducted on 330 medical students (males=140 and females=190) of a public institute from April to September 2019. Cases include students who were diagnosed with myopia and wear glasses or contact lenses for it. Whereas controls were the students without any visual defect. Data was collected through non-probability convenience sampling from participants between 18 to 25 years from all five years of MBBS. Those with vision defects other than myopia, like hypermetropia, keratoconus, glaucoma, etc., were excluded. Data were entered and analyzed using Statistical Package for Social Sciences (SPSS) version 25 by applying the non-parametric tests and descriptive statistics.
Results: Among 330 participants, 185 (56%) had myopia, which increased rapidly between the age of 15 to 20 years in the majority (58.4%) of them. 52.5 % of myopics had a positive family history of myopia. Males were less likely to develop myopia than females (OR=0.65). There was no statistically significant difference in sleeping hours (p-value=0.46), screen exposure time (p-value=0.78) or study hours (p-value=0.15) between myopics and non-myopics. Both groups often take breaks during the study. However, non-myopics were significantly more physically active than myopics (p-value=0.025), which shows that low physical activity is associated with the development of myopia.
Conclusion: There is not any significant effect of sleeping hours, screen exposure time, study hours, or breaks during the study on myopia. Myopia is more prevalent in people with a family history of myopia, females, and those with little physical activity.
2. Chua J, Wong T. Myopia—The Silent Epidemic That Should Not Be Ignored. JAMA Ophthalmology. 2016;134(12):1363.
3. Holden B, Fricke T, Wilson D, Jong M, Naidoo K, Sankaridurg P et al. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-1042.
4. Harrington S, Stack J, O'Dwyer V. Risk factors associated with myopia in schoolchildren in Ireland. British Journal of Ophthalmology. 2019;:bjophthalmol-2018-313325.
5. Ostrin L, Read S, Vincent S, Collins M. Sleep in Myopic and Non-Myopic Children. Translational Vision Science & Technology. 2020;9(9):22.
6. Wei S, Li S, Liu L, Li H, Kang M, Sun Y et al. Sleep Duration, Bedtime, and Myopia Progression in a 4-Year Follow-up of Chinese Children: The Anyang Childhood Eye Study. Investigative Ophthalmology & Visual Science. 2020;61(3):37.
7. Saw S, Hong C, Chia K, Stone R, Tan D. Nearwork and myopia in young children. The Lancet. 2001;357(9253):390.
8. Read S, Collins M, Vincent S. Light Exposure and Physical Activity in Myopic and Emmetropic Children. Optometry and Vision Science. 2014;:1.
9. Walline J, Smith M. Controlling myopia progression in children and adolescents. Adolescent Health, Medicine and Therapeutics. 2015;:133.
10. French A, Morgan I, Mitchell P, Rose K. Risk Factors for Incident Myopia in Australian Schoolchildren. Ophthalmology. 2013;120(10):2100-2108.
11. Hussain Lashari M, Ayub, R, SaleemAkhta M. Correlates of myopia in students of BahauddinZakariya University, Multan. JPMA: Journal Of Pakistan Medical Association. 2017;67:1920-1922.
12. Pärssinen O, Kauppinen M, Viljanen A. The progression of myopia from its onset at age 8–12 to adulthood and the influence of heredity and external factors on myopic progression. A 23‐year follow‐up study. Acta Ophthalmol. 2014;92(8):730-739.
13. Xu C, Pan C, Zhao C, Bi M, Ma Q, Cheng J, et al. Prevalence and risk factors for myopia in older adult east Chinese population. BMC Ophthalmol. 2017;17(1):191.
14. Wei SF, Li SM, Liu L, Li H, Kang MT, Sun YY, et al. Sleep Duration, Bedtime, and Myopia Progression in a 4-Year Follow-up of Chinese Children: The Anyang Childhood Eye Study. Invest Ophthalmol Vis Sci. 2020;61(3):37.
15. Guggenheim J, Northstone K, McMahon G, Ness A, Deere K, Mattocks C et al. Time Outdoors and Physical Activity as Predictors of Incident Myopia in Childhood: A Prospective Cohort Study. Investigative Ophthalmology & Visual Science. 2012;53(6):2856.
16. Rose K, Morgan I, Ip J, Kifley A, Huynh S, Smith W et al. Outdoor Activity Reduces the Prevalence of Myopia in Children. Ophthalmology. 2008;115(8):1279-1285.
17. Cohen Y, Peleg E, Belkin M, Polat U, Solomon A. Ambient illuminance, retinal dopamine release and refractive development in chicks. Experimental Eye Research. 2012;103:33-40.
18. Thomson K, Karouta C, Ashby R. Form-Deprivation and Lens-Induced Myopia Are Similarly Affected by Pharmacological Manipulation of the Dopaminergic System in Chicks. Investigative Ophthalmology & Visual Science. 2020;61(12):4.
19. Nickla D, Sarfare S, McGeehan B, Wei W, Elin-Calcador J, He L et al. Visual conditions affecting eye growth alter diurnal levels of vitreous DOPAC. Experimental Eye Research. 2020;200:108226.
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