Exfoliation glaucoma.
Geographic latitude and outside air temperature—not ethnicity—could be potential risk factors for the development of exfoliation syndrome (ES), according to a study published in the January issue of Ophthalmology.

Exfoliation syndrome is the leading cause of secondary open-angle glaucoma, and may also contribute to cataract formation.

In this study, researchers from the Massachusetts Eye and Ear Infirmary at Harvard Medical School examined the records of 78,955 females enrolled in the Nurses’ Health Study and 41,191 males enrolled in the Health Professionals Follow-up Study for descriptive epidemiologic features of ES.

The researchers determined that:

  • Females were at a higher risk for ES.
  • Individuals with a positive family history of glaucoma were more than twice as likely to develop ES.
  • Individuals of Scandinavian or Southern European descent are not genetically predisposed to the development of ES.
  • Iris color was not a risk factor for ES.

“This large, prospective cohort study demonstrates that there is a positive association between latitude and ES risk that is robust and not related to demographic features or other systemic covariates,” said study co-author Louis Pasquale, M.D., director of Massachusetts Eye and Ear.

Once the researchers realized that ethnicity was not a significant risk factor for ES, they suggested that the disease might have an environmental component.

“Importantly, those with a lifetime residential history of living in the middle tier and south tier of the United States was associated with 47% and 75% reduced risks, respectively, compared with living in the northern tier,” the authors wrote.

Another manuscript they recently published suggests that lower ambient temperature interacts with increased solar exposure to heighten the risk of ES.

More research needs to be done to determine how these environmental factors contribute to ES, they add.

Kang JH, Loomis S, Wiggs JL, et al. Demographic and geographic features of exfoliation glaucoma in 2 United States-based prospective cohorts. Ophthalmology. 2012 Jan;119(1):27-35.