A study in Environmental Health Perspectives suggests long-term lead exposure may be a risk factor for primary open-angle glaucoma (POAG), the most common form of glaucoma.
What Causes Glaucoma?
Glaucoma is an eye disease that damages the optic nerve and can cause permanent vision loss if not promptly diagnosed. Glaucoma affects more than three million Americans and is the leading cause of irreversible blindness.
The causes of glaucoma are not fully understood, but researchers have identified certain glaucoma risk factors in regard to age, heredity, health history and medications. This particular study is groundbreaking because it claims that environmental factors could affect glaucoma risk.
Bone Lead Levels Affect Glaucoma Risk
Sung Kyun Park, an environmental health scientist at the University of Michigan, wanted to learn if there was a connection between chronic lead exposure and glaucoma incidence. Blood tests are currently inadequate because they measure recent exposure to lead. Bones, however, store lead for decades, so lead levels in the patella (knee) and tibia (leg) provide accurate data.
Park analyzed patella and tibia lead levels from a subset of participants in the Veterans Affairs Normative Aging Study, a study that has followed 2,280 men since 1963. The research team tracked ophthalmologic and bone lead level data on 634 men and identified 44 new cases of primary open-angle glaucoma (POAG).
Park estimates POAG risk was about “five times higher with a 10-fold increase in patella lead and about three times higher with a 10-fold increase in tibia lead” (EHP).
Although Park’s study suggests a link between long-term lead exposure and POAG, his findings still need to be confirmed within a larger sample size that includes women. Park is also interested in whether there is a correlation between POAG and exposure to other metals as well as early-life exposure.
Glaucoma Symptoms and Signs
Glaucoma is often a mystery in terms of its cause and development. In most cases of POAG, there are no symptoms or pain. This is why it is nicknamed the “sneak thief of sight.” One of the first symptoms of glaucoma is peripheral vision loss, but by that point, permanent eye damage has already occurred.
The best way to preserve your vision is to schedule annual comprehensive eye exams with your ophthalmologist. Your doctor will evaluate your eye health and perform tests to measure the pressure inside your eye. If the doctor detects signs of glaucoma, treatment can begin immediately.