PARIS A French epidemiological study on a large number of cases
demonstrated significant correlations between age-related macular degeneration,
complement factor H Y402H polymorphism, smoking and high HDL-cholesterol
The association between the [complement factor H, CFH] gene and
the risk for neovascular AMD, particularly in homozygote subjects, was already
established by several studies. CFH plays a role in inflammation, which was
therefore proven to be an important component of the macular age-related
disease, Marie Bénedicte Renaud Rougier, MD, said at the meeting
of the French Society of Ophthalmology here. Also, advanced AMD was shown
to be two to three times more frequent amongst smokers in a number of
CFH Y402H polymorphism
The French, population-based ALIENOR (Antioxydants, lipides essentiels,
nutrition et maladies oculaires) study, carried out at the University of
Bordeaux, confirmed these data by analyzing a cohort of 963 subjects aged 65
years or older.
The Y402H polymorphism of CFH was determined in 878 (91.2%) cases. In
796 of these subjects, eye fundus images could be analyzed and classified in
five stages according to the international classification of age-related
maculopathy (ARM): stage 0 for no sign of macular disease, stage 1 and 2 for
ARMs, and stage 3 and 4 for AMD, geographic atrophy and neovascular AMD.
The CFH Y402H polymorphism was strongly associated with
neovascular AMD and with stage 2, early ARM. Adjustment for smoking did not
modify the association, and this is important because smoking decreases the
plasma concentration of CFH, Dr. Renaud Rougier said.
Cumulative effect of smoking
Smoking was equally associated with stage 4, neovascular AMD and with
early stage 2 ARM.
There was a relatively low number of smokers (46 subjects) in this
age group, and the correlation with the risk of age-related macular pathologies
was major, Dr. Renaud Rougier said. The risk is cumulative: It
increases with the number of packets per year.
Adjustment for CFH did not modify the association.
The part of the ALIENOR study presented by Dr. Renaud Rougier confirmed
the contribution of CFH and smoking to the etiology of ARM. Another part of the
study analyzed the correlation between HDL-cholesterol levels and the five
stages of ARM in the same cohort of patients. A positive association was found
with all stages of ARM, reaching statistical significance for stages 2 and 4.
by Michela Cimberle