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Freeman, Cataract Surgery and Age-Related Macular Degeneration
associated with early AMD 1. Severe cataract was also not associated with early AMD 1 in SEE
or in BES.
Neither cataract surgery nor severe cataract were associated with the odds of early AMD
2 in either SEE or BES (Table 7), as none of the estimates were statistically significant and no
consistent trends were apparent.
DISCUSSION
These analyses based on data from three independent, population-based studies provide
some evidence that previous cataract surgery may be associated with a higher prevalence of late
AMD. In all studies, the odds ratios for previous cataract surgery and late AMD were greater
than 1, although they varied in magnitude from 1.3-2.6. The reasons for this variation are not
clear, but may be due to differences in the population that could not be controlled for. It could
also be due to the small number of cases of late AMD, which can lead to unstable measures of
association. In addition, the assessment of AMD differed in PVER, compared to BES and SEE.
When data from the three populations were pooled, the combined odds ratio was 1.7, which was
statistically significant.
In addition, at first glance, it appeared that increasing time since cataract surgery was
associated with a higher prevalence of late AMD. In the BES study, those who had cataract
surgery >=5 years ago had an increased prevalence of late AMD, although this was not
statistically significant. The SEE study showed a similar trend, although sensitivity analyses
showed that this trend was due to a bias caused by the missing dates of surgery.
Our overall findings are in agreement with the prospective Beaver Dam results, which
found previous cataract surgery to be associated with a higher 10-year incidence of late AMD
(RR=3.8, 95% CI 1.9-7.7)
8
. They also found previous cataract surgery to be associated with a
