An Objective Biomarker Of Ocular Sun Exposure Is Inversely Correlated With Myopia In Young Adults: The Raine Eye Health Study

An Objective Biomarker Of Ocular Sun Exposure Is Inversely Correlated With Myopia In Young Adults: The Raine Eye Health Study

Charlotte M. McKnight, Seyhan Yazar, Justin Sherwin, Hannah Forward, Alex Tan, Terri L. Young, Christopher J. Hammond, Craig Pennell, Minas T. Coroneo, David A. Mackey. 

Centre for Ophthalmology & Visual Science, University of Western Australia, Lions Eye Institute, Crawley, Australia; Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom; Ophthalmology, Duke University Eye Center, Durham, NC; Ophthalmology, King's College London, London, United Kingdom; School of Women's and Infants' Health, University of Western Australia, Subiaco, Australia; Ophthal-Prince of Wales Hosp, Univ of New South Wales, Randwick, Australia; Lions Eye Institute, Perth, Australia.

This abstract is from the ARVO (The Association for Research in Vision and Ophtalmology) website.  This cross-sectional study was presented at the May 2012 meeting.  Many articles on myopia were presented at that meeting.  This one measured ocular sun exposure objectively using conjunctival ultraviolet autofluorescence photography which the authors describe as "an objective, quantitative and reliable method of assessing ocular sun exposure".  The study found that there was a relationship between myopia and ocular sun exposure measured this way: the higher the degree of myopia, the lower the amount of ocular sun exposure measured.  So this supports other studies that found that the more time children are outdoors, exposed to sunlight, the lower their risk of myopia.

From the text:

"Several studies have demonstrated an inverse association between outdoor activity and myopia. Many of these studies have been limited by subjective measurement of outdoor activity, such as parental or participant recall via questionnaire. We used conjunctival ultraviolet autofluorescence photography, an objective, quantitative and reliable method of assessing ocular sun exposure, to investigate the relationship between outdoor activity, ultraviolet light exposure and myopia.

This was a cross-sectional study of 1231 young adults aged 19 to 22 years in the Raine cohort, Western Australia. Ultraviolet fluorescence images of the interpalpebral conjunctiva (right and left eye, nasal and temporal regions) were taken using a specially designed camera system.

Prevalence of myopia decreased with increasing quartiles of conjunctival autofluorescence, with 32.8% in the lowest quartile, 28.0% in the second quartile, 17.2% in the third quartile and 15.6% in the highest quartile. Participants in the lowest quartile had 2.6 times the odds of myopia than those in the highest quartile (95% confidence interval 1.7 to 3.8, p<0.001). The inverse association between myopia and conjunctival autofluorescence remained significant after adjustment for age, gender, time outdoors, educational activity and parental history of myopia (OR 2.5, 95% confidence interval 1.5 to 4.2, p<0.001).

These findings have implications for our understanding of myopia pathogenesis, of particular importance given the increasing prevalence of myopia worldwide. As causality cannot be inferred given the cross-sectional design of this study, prospective studies looking at conjunctival autofluorescence and development of myopia are required."

LInk:

http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=b5b23b76-e553-4547-aebf-1968a6cf8f47&cKey=6d208530-5bce-4bf8-b88d-055dd03c15a2&mKey=%7bF0FCE029-9BF8-4E7C-B48E-9FF7711D4A0E%7d