Myopia and skin cancer are inversely correlated: Results of the Busselton Healthy Ageing Study

Abstract

Purpose: Spending time outdoors, with the associated ultraviolet (UV) irradiation, is a well-established risk factor for developing skin cancer. In contrast, outdoor activity is protective against myopia. We sought to determine the distribution of refractive error amongst individuals previously diagnosed with basal cell carcinoma, squamous cell carcinoma or cutaneous melanoma.

Methods: The Busselton Healthy Ageing Study is a cross-sectional survey of individuals born between 1946-1964 living in the coastal community of Busselton, located in the south-west of Western Australian. Our cohort included 2023 participants of the Busselton Healthy Ageing Study. Participants completed a questionnaire including their previous medical and ocular history. Refractive error was measured by cycloplegic autorefraction using the Nidek ARK-510A (NIDEK Co.Ltd, Japan).

Results: Complete data were available for 1928 participants (mean age 56.3 years, range 45.5-66.4 years, 53.5% male) of Northern European ancestry. Of these, 146 (8%) had a previous history of skin cancer. Median spherical equivalent (SE) was +0.44 D (IQR: -0.06, +1.13) in the skin cancer group and +0.38 D (IQR: -0.31, +1.00) in the control group (p=0.05). In a regression model adjusted for age, sex and education, the odds of being non-myopic was 2.35 (95%CI: 1.42 - 4.11) times higher in the skin cancer group than controls (p=0.001). For every 1.00 D increase in mean SE, the odds of having skin cancer increased by factor of 1.18 (95%CI: 1.04 - 1.34) (p=0.01).

Conclusions: These findings support the hypothesis that spending time outdoors lessens an individuals’ risk for developing refractive error. However, recommendations to increase outdoor activity in childhood to prevent myopia must also take into account the harmful effects of UV radiation and increased risk of skin cancers.

Keywords: 605 myopia