Every individual that ever smoked cigarettes was
associated with an increased risk of age-related cataract
13, 2012 – Cigarette smoking is a well-known risk factor for a
wide-range of diseases. Now, scientists have evidence that smoking may
also increase the risk of age-related cataract, the leading cause of
blindness and vision loss in the world.
Reported in Investigative Ophthalmology & Visual
Science (Smoking and Risk of Age-related Cataract: A Meta-analysis),
the new findings are the result of a meta-analysis conducted by a team
of researchers from China.
"Although cataracts can be removed surgically to
restore sight, many people remain blind from cataracts due to inadequate
surgical services and high surgery expenses," said author Juan Ye, MD,
PhD, of the Institute of Ophthalmology, Zhejiang University in China.
"Identifying modifiable risk factors for cataracts may help establish
preventive measures and reduce the financial as well as clinical burden
caused by the disease."
The team performed the analysis using 12 cohorts
and eight case-control studies from Africa, Asia, Australia, Europe and
North America, to compare the prevalence of age-related cataract in
individuals who ever smoked cigarettes to those who have never smoked.
Further subgroup analyses were performed based on the subjects' status
as a past or current smoker and the three subtypes of age-related
The results showed that every individual that ever
smoked cigarettes was associated with an increased risk of age-related
cataract, with a higher risk of incidence in current smokers. In the
subgroup analysis, former and current smokers showed a positive
association with two of the subtypes: nuclear cataract, when the
clouding is in the central nucleus of the eye, and subscapular cataract,
when the clouding is in the rear of the lens capsule.
The analysis found no association between smoking
and cortical cataract, in which the cloudiness affects the cortex of the
While the overall analysis suggests that smoking
cigarettes may increase the risk of age-related cataracts, the
researchers point out that further effort should be made to clarify the
"We think our analysis may inspire more
high-quality epidemiological studies" said Ye. "Our analysis shows that
association between smoking and the risk of age-related cataract differ
by subtypes, suggesting that pathophysiologic processes may differ in
the different cataract types."
The ARVO peer-reviewed journal Investigative
Ophthalmology & Visual Science (IOVS) publishes results from
original hypothesis-based clinical and laboratory research studies, as
well as Reviews, Perspectives, and Special Issues. IOVS 2009 Impact
Factor ranks No. 4 out of 45 among ophthalmology journals. The journal
is online-only and articles are published daily.
The Association for Research and Vision in
Ophthalmology (ARVO) is the largest eye and vision research organization
in the world. Members include more than 12,500 eye and vision
researchers from over 80 countries. ARVO encourages and assists
research, training, publication and knowledge-sharing in vision and