This matches up with the
Netherlands study in 2011. So ask your wise doctor what you should be doing. In the last 2 years has your doctor talked to you about this?
http://www.medpagetoday.com/Ophthalmology/GeneralOphthalmology/36943?
Regular aspirin use was associated with an elevated risk for
neovascular age-related macular degeneration, an Australian study
suggested, but actual causality remains uncertain.
After adjustment for age, sex, and history of smoking, the odds ratio
for macular degeneration in aspirin users was 2.37 (95% CI 1.25 to
4.49), according to Jie Jin Wang, PhD, of the University of Sydney, and
colleagues.
With further adjustment for body mass index, systolic blood pressure,
and history of cardiovascular disease (CVD), the association remained
(OR 2.46, 95% CI 1.25 to 4.83), the researchers reported online in
JAMA Internal Medicine.
However, "the evidence is insufficient to adjudicate the relationship
between aspirin and [age-related macular degeneration], thereby
challenging causal inferences," Sanjay Kaul, MD, and George A. Diamond,
MD, of Cedars-Sinai Medical Center in Los Angeles, wrote in an invited
commentary.
A recent cross-sectional study suggested a possible link between
neovascular age-related macular degeneration and routine aspirin use,
but other studies have yielded conflicting findings.
To prospectively examine this potential link, Wang and colleagues
analyzed data from the Blue Mountains Eye Study, which included 2,389
Australians ages 49 and older.
Retinal examinations were done every 5 years, and lesions classified
as neovascular, or wet macular degeneration, or geographic atrophy, also
known as dry macular degeneration.
Aspirin use was reported on a structured questionnaire, and
information on relevant risk factors was obtained during physical
examination and history reports.
A total of 257 participants were regular aspirin users. Compared with
nonusers, they were older and more often had conditions such as
diabetes, cardiovascular disease, or elevated blood pressure.
During 15 years of follow-up, age-related wet macular degeneration was identified in 63 individuals.
Among regular users, the cumulative incidence was 1.9%, 7%, and 9.3%
at years 5, 10, and 15, while the incidence among nonusers was 0.8%,
1.6%, and 3.7%, respectively.
The incidence of neovascular macular degeneration rose with more
frequent aspirin use, increasing from 2.2% in those who never took
aspirin, to 2.9% for those who used it only occasionally, and 5.8% for
those who took aspirin routinely.
Aspirin use was not associated with risk for geographic atrophy.
Additional secondary analyses found that the risk was four times
higher in patients with a history of CVD (OR 4.36, 95% CI 1.24 to 15.32)
and in those without a polymorphism on
CFHY402H, a gene involved in the complement pathway that has been linked with macular degeneration (OR 4.17, 95% CI 1.05 to 16.49).
The researchers also considered whether other medications often taken
by aspirin users, such as acetaminophen and beta-blockers, might
influence risk, and the results were negative.
These results create a quandary for the many patients using aspirin,
particularly those taking the drug as secondary prevention of CVD,
according to Wang's group.
"Aspirin is one of the most effective CVD treatments and reduces recurrent CVD events by one-fifth," they observed.
However, significant adverse events can occur, such as cerebral and gastrointestinal bleeding.
"Our present study now raises the possibility that the risk of
neovascular [age-related macular degeneration] may also need to be
considered," they stated.
Nonetheless, they conceded that the risk is small, at slightly under
4% over 15 years, and the evidence is thus far insufficient to support a
change in practice away from widespread aspirin use, except for
patients at very high risk for macular degeneration.
Any risk-benefit analysis also must consider the availability of
effective -- but expensive -- treatments for neovascular age-related
macular degeneration.
"Any decision concerning whether to stop aspirin is thus complex and needs to be individualized," they wrote.
Limitations of the study included the possibility of confounding by
indication and a lack of information on the reasons why participants
were taking aspirin.
In their invited commentary, Kaul and Diamond wrote, "These findings
are, at best, hypothesis-generating that should await validation in
prospective randomized studies before guiding clinical practice or
patient behavior."
They also advised that the choice of whether to use aspirin should
focus on whether the indication is for secondary CVD prevention, "where
the benefits of aspirin are indisputable and greatly exceed the risk,"
or for primary prevention, where the evidence is less clear, as well as
the extent of the person's risk for macular degeneration and bleeding.
"In the final analysis, decisions about aspirin use are best made by
balancing the risks against the benefits in the context of each
individual's medical history and value judgments," they added.
Other experts, such as Shawn Wilker, MD, of University Hospitals Case
Medical Center in Cleveland, agreed on the importance of individual
risk.
"I think a reasonable circumstance when you could ask a patient not
to take aspirin might be one in which there is a very low risk of
mortality from cardiovascular disease or if that person is at very great
risk of losing vision from macular degeneration," Wilker said in an
interview.
Journal editor Kenneth E. Covinsky, MD, also weighed in in an
editor's note, stating that "as with many good studies, the data are not
definitive enough to suggest changes in clinical practice."
"Rather, we hope the study galvanizes more research on the
relationship between aspirin and macular degeneration," Covinsky wrote.
