Program No.: 223
Risk Factors of Age-Related Macular Degeneration in Argentina
Van C. Lansingh MD PhD,1 Maria E Nano MPH,2 Marissa J Carter MA PhD,3 Kristen A Eckert MPhil,3 Luciana Fiocca Vernengo MD,4 Jose D Luna MD,4
Natalia S Zarate BA,2 Hugo Nano MD,2 Clelia Crespo Nano MD,2 Joao M Furtado MD PhD5
1International Agency for the Prevention of Blindness (IAPB), Weston, FL, USA; 2Fundacion Nano, Buenos Aires, Argentina; 3Strategic Solutions, Inc., Cody
WY, USA; 4Centro Privado de Ojos Romagosa, Cordoba Argentina; 5Federal University of Sao Paulo, Sao Paulo, Brazil
Conflicts of Interest: None; email: [email protected]
Purpose
Age-related
macular
degeneration
(AMD) causes 5% of global blindness
and 1% of visual impairment. In Latin
America, little research has been done
on the disease. Argentina has one of
the highest elderly populations in the
region with up to 13.1% being 65 years
or older. Despite its significantly aging
population, there have been no studies
to date on AMD in Argentina, where
epidemiological studies on blindness
suggest that AMD may be the cause of
3-4% of blindness. The purpose of this
case-control study is to assess the risk
factors for the development and
progression of AMD in Argentina.
Methods
Twenty-eight ophthalmologists from
Buenos Aires City and 5 interior
provinces surveyed patients on the
possible risk factors of AMD. Surveys
were used for patients’ antioxidant
intake, age/gender, race, body mass
index (BMI), hypertension, diabetes
(and type of treatment), smoking,
sunlight
exposure,
red
meat
consumption, fish consumption, and the
presence of AMD. Ophthalmological
examination composed of indirect
ophthalmoscopy and Amsler grid was
performed. Patients were classified
according to the severity of their AMD
lesions. Patients presenting no signs of
AMD were used as controls. Results
were analyzed with main effects models
for logistic regression and ordinal
logistic regression.
Results
There were 175 cases and 175
controls with a mean age of 75.4 years
and 75.5 years, respectively, of whom
236 (67.4%) were female. One
hundred and fifty-nine (45.4%) had
AMD in their left eyes, 154 (44.0%) in
their right eyes, and 138 (39.4%) in
both eyes. Of the cases with AMD in
their left eyes, 47.8% had the dry type,
40.3% had the wet type, and the type
was unknown for 11.9%. The
comparable figures for right eyes
were: 51.9%, 34.4%, and 13.7%,
respectively. The main effects model
was dominated by higher sunlight
exposure (OR [odds ratio]: 3.3) and a
family history of AMD (OR: 4.3). Other
factors included hypertension (OR:
2.1), smoking (OR: 2.2), and being of
the Mestizo race, which lowered the
risk of AMD (OR: 0.40). Red meat/fish
consumption, BMI, and iris color did
not have an effect. Higher age was
associated with progression to more
severe AMD.
Conclusions
Sunlight exposure, family history of AMD,
and an older age were the significant risk
factors. There may be other variables, as
the risk was not explained very well by
the existing factors. A larger sample may
produce different and better results.
The authors would like to
thank ORBIS for their
financial support of this
project.
Table 1. Main effects model, logistic regression
Parameter
B*
SE†
Race
P‡
OR§
95% CI||
0.016
Mestizo
-.924
0.363
0.011
0.397
0.20-0.81
Other
-.931
0.618
0.132
0.394
0.12-1.32
Hypertension
0.752
0.247
0.002
2.122
1.31-3.44
Smoker
0.782
0.357
0.028
2.187
1.09-4.40
3.281
1.91-5.62
Moderate-to-heavy
sunlight exposure
1.188
0.275
1.5 x
10-5
7.8 x 10-6
AMD familial history
Yes
1.465
0.371
7.9 x 10-5
4.329
2.09-8.96
Unknown
1.067
0.263
5.1 x 10-5
2.907
1.74-4.87
*B: logistic coefficients; †SE: standard error; ‡P (value): significance; §OR: odds
ratio; ||CI: confidence intervals. The reference for race is White, for hypertension
no hypertension, for smoking status no smoking, for sunlight exposure light-tomoderate exposure (0-6 hours of sunlight exposure per day), and for age-related
macular degeneration (AMD) familial history no history of AMD.
Table 2. Main effects model, ordinal logistic regression
Parameter
BMI category||
Obese
Overweight
Age category (years) ¶
˃ 84
80-84
75-79
70-74
65-69
*Coefficients
B Coefficient*
P†
OR‡
95% CI§
-1.041
-.280
0.007
0.478
2.83
1.32
1.33-6.06
0.61-2.86
3.859
2.697
2.020
1.593
1.042
5.6 x 10-6
0.000045
0.001
0.012
0.117
0.021
0.067
0.133
0.203
0.353
0.004-0.110
0.018-0.250
0.039-0.450
0.059-0.700
0.096-1.300
for the predictor variables; †P (value): significance; ‡OR: odds
confidence intervals; ||BMI: Body Mass Index reference is normal or
ratio;
slightly underweight (18.5kg/m2 and <25kg/m2); ¶Reference is < 65 years.
§CI:
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