Sunlight Exposure: A Protective Role in the Development of Myopia

Abstract

The study objective was to assess the correlation of time outdoors in sunlight hours with spherical equivalent refraction (SER) and other variables. This was a cross-sectional study carried out in the Fauji Foundation Hospital, Rawalpindi, between January and April 2019. A total of 110 Individuals were included via convenient sampling, with myopia defined as having at least -0.5 D (SER ≤ -0.5 D). Collection of Questionnaires with interviews regarding eye care behaviour along with auto-refraction was done, followed by calculation of spherical equivalent refraction. Those having high myopia of 6 D or more (SER ≤ - 6 D), hyperopia of 0.5 D or more (SER ≥ +0.5 D), and history significant for ocular trauma and surgeries, were excluded. After data cleaning and their entry, analyses were done using SPSS version 26. The mean age data, available for 105 individuals, was 15.4 ± 3.69 years. Spearman's correlation was used for right SER with time outdoors in summers (r= +0.25, p=0.008) and winters (r= +0.243, p=0.010), indicating an inverse relationship with myopia. Females had more myopic refraction than males, but the independent sample t-test was not significant. Logistic regression was used and a protective effect was found for both summer and winter time outdoors, while education level was associated with myopia. Key Words: Myopia, Spherical equivalent refraction (SER), Sunlight exposure.