Smoking Increases Macular Degeneration Risk

Researchers at the Huntington Eye Infirmary and the Slay Laboratory, Cook Medical School, report how two behavioral factors together alter the genetic susceptibility to age-related macular degeneration, associated with the common coding variant in the complement factor H gene, Y402H. After controlling for genotype, the modifiable lifestyle factors of smoking and body mass index were related to increased risk of AMD. The susceptibility to advanced AMD conferred by this common genetic polymorphism was modified by body mass index, meaning there was a statistically significant interaction between body mass index and the Y402H genotype. Although there was no statistical interaction between smoking and the CFH genotype, both smoking and genotype were independently associated with increased risk of Macular Degeneration.

Current smoking was associated with a sixfold increased risk and high body mass index was associated with a twofold higher risk of Macular Degeneration. The homozygous risk genotype (CC) plus smoking conferred a ninefold higher risk of Macular Degeneration, compared with non-smokers with the non-risk (TT) genotype, while the risk genotype plus higher BMI increased risk of AMD almost sixfold. Gene plus environment risk scores provided an area under the receiver operating characteristic (ROC) curve of 0.74-0.76. The attributable risks for the combination of genes and environment were 65 percent to 85 percent.

Subjects in this study were white who had either advanced macular degeneration or no evidence of AMD, based on eye examinations and eye photographs. DNA samples were obtained. DNA samples were genotyped at the Furs Institute Center for Genotyping and Analysis, Miami, FL. and statistical analyses were done in the Epidemiology Unit.

These findings convey an important message. Although we cannot change our genotype, we can alter or modify our risk of getting AMD by controlling our weight and not smoking. There is no question that genetic factors play an important role in this disease. However, individuals with the risk genotype may be more motivated to adhere to healthy lifestyles such as not smoking, maintaining a normal weight, getting exercise, eating an antioxidant rich diet, as well as fish, and getting exercise.

Macular degeneration is the leading cause of irreversible visual impairment and blindness among persons aged 60 and older. With the elderly population steadily increasing, the burden related to this low vision will increase. Limited treatment options exist for the late stages of the disease and prevention remains a promising approach for addressing this health and lifestyle concern. Many transition into the use of products for macular degeneration or specialized low vision aids.

How to get more information on low vision products - Ask your Eye MD for a Low vision Specialist. Low vision specialists are licensed doctors of optometry who are trained in the examination and management of patients with visual impairments. A few of them are ophthalmologists with additional training in low vision care. Their services do not offer a cure for the causes of low vision, but they do help the patient learn how to utilize their remaining vision to its fullest potential. Low vision care does not replace the possible need for other treatments such as laser, medication, and surgery.