Distribution of conjunctival ultraviolet autofluorescence in a population-based study: the Norfolk Island Eye Study
Sherwin, JC and Hewitt, AW and Kearns, LS and Coroneo, MT and Griffiths, LR and Mackey, DA, Distribution of conjunctival ultraviolet autofluorescence in a population-based study: the Norfolk Island Eye Study, Eye, 25, (7) pp. 893-900. ISSN 0950-222X (2011) [Refereed Article]
Objective The objective of this study was to
describe the distribution of conjunctival
ultraviolet autofluorescence (UVAF) in an
Methods We conducted a cross-sectional,
population-based study in the genetic isolate
of Norfolk Island, South Pacific Ocean. In all,
641 people, aged 15 to 89 years, were recruited.
UVAF and standard (control) photographs
were taken of the nasal and temporal
interpalpebral regions bilaterally. Differences
between the groups for non-normally
distributed continuous variables were
assessed using the Wilcoxon–Mann–Whitney
ranksum test. Trends across categories were
assessed using Cuzick’s non-parametric test
for trend or Kendall’s rank correlation s.
Results Conjunctival UVAF is a nonparametric
trait with a positively skewed
distribution. Median amount of conjunctival
UVAF per person (sum of four measurements;
right nasal/temporal and left nasal/temporal)
was 28.2mm2 (interquartile range 14.5–48.2).
There was an inverse, linear relationship
between UVAF and advancing age (Po0.001).
Males had a higher sum of UVAF compared
with females (34.4mm2 vs 23.2mm2,
Po0.0001). There were no statistically
significant differences in area of UVAF
between right and left eyes or between nasal
and temporal regions.
Conclusion We have provided the first
quantifiable estimates of conjunctival UVAF
in an adult population. Further data are
required to provide information about the
natural history of UVAF and to characterise
other potential disease associations with
UVAF. UVR protective strategies should be
emphasised at an early age to prevent the
long-term adverse effects on health associated
with excess UVR.