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The use of conjunctival ultraviolet autofluorescence (CUVAF) as a biomarker of time spent outdoors.

Kearney, Stephanie, O'Donoghue, Lisa, Pourshahidi, L. Kirsty, Richardson, Patrick and Saunders, Kathryn J (2016) The use of conjunctival ultraviolet autofluorescence (CUVAF) as a biomarker of time spent outdoors. Ophthalmic and Physiological Optics, 36 (4). p. 359. [Journal article]

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URL: https://www.ncbi.nlm.nih.gov/pubmed/27350182

DOI: 10.1111/opo.12309

Abstract

Purpose: CUVAF has been used in previous Southern Hemisphere myopia research as a marker for time spent outdoors. The validity of CUVAF as an indicator of time spent outdoors is yet to be explored in the Northern Hemisphere. It is unclear if CUVAF represents damage attributed to UV exposure or dry eye. This cross-sectional study investigated the association between CUVAF measures, self-reported time spent outdoors and measures of dry eye.Methods: Participants were recruited from University staff and students (n=50, 19-64yrs; mean 41). None were using topical ocular medications (with the exception of dry eye treatments). Sun exposure and dry eye questionnaires (Ocular Surface Disease Index (OSDI) and McMonnies) were completed by the participant. Dryness was also assessed using slit lamp biomicroscopy and invasive tear break up time (ITBUT). Images of the temporal and nasal conjunctiva from the right and left eye were captured using a bespoke photography system. The total CUVAF area, average CUVAF pixel intensity per mm2 and total CUVAF pixel intensity were analysed using MATLAB R2013a (The MathWorks Inc).Results: Of the 50 participants, 42% were classified as having dry eye. Self-reported sunglass use was negatively associated with all CUVAF measures (Kruskal Wallis total CUVAF area, p=0.04, ptrend=0.03, average CUVAF pixel intensity p=0.02, ptrend= 0.02, total CUVAF pixel intensity: p=0.04, ptrend=0.02). Time spent outdoors was positively associated with all CUVAF measures (Spearman’s corr. total CUVAF area: r=0.37, p=0.01, average CUVAF pixel intensity: r=0.36, p=0.01, total CUVAF pixel intensity: r=0.37, p=0.01) and remained significant when sunglass use was controlled for (partial correlation, total CUVAF area: r=0.32, p=0.03, average CUVAF pixel intensity: r=0.39, p=0.01, total CUVAF pixel intensity: r=0.39, p=0.03). Neither CUVAF area nor intensity measures were associated with any dry eye measure (OSDI: all p≥0.41, corneal staining: all p≥0.38, McMonnies: all r≤0.09 all p≥0.52, slit lamp biomicroscopy: all r≤0.20 all p≥0.17, ITBUT: all r≤-0.07 all p≥0.31).Conclusions: CUVAF area and intensity were not associated with clinical measures of dry eye. Greater CUVAF area and intensity were associated with wearing sunglasses less frequently and spending more time outdoors. If sunglass wear is accounted for, CUVAF may be a useful biomarker of time spent outdoors in future myopia studies.

Item Type:Journal article
Keywords:myopia, autofluorescence, dry eye
Faculties and Schools:Faculty of Life and Health Sciences > School of Biomedical Sciences
Faculty of Life and Health Sciences
Research Institutes and Groups:Biomedical Sciences Research Institute > Nutrition Innovation Centre for Food and Health (NICHE)
Biomedical Sciences Research Institute
Biomedical Sciences Research Institute > Optometry and Vision Science
ID Code:34741
Deposited By: Professor Kathryn Saunders
Deposited On:02 Jun 2016 14:29
Last Modified:17 Oct 2017 16:23

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