Residential geography, time spent in the sun, and whether or not sunglasses are worn may help explain why some people develop exfoliation syndrome (XFS), an eye condition that is a leading cause of secondary open-angle glaucoma and can lead to an increased risk of cataract and cataract surgery complications, according to a study published on Sept. 4 in JAMA, Ophthalmology.

Despite improvements in understanding the cause of this common yet life-altering condition, more work needs to be done. “The discovery that common genetic variants in the lysyl oxidase-like 1 gene (LOXL1) are associated with 99 percent of XFS cases represented a significant advance in our understanding of this condition,” said the study’s lead author, Louis Pasquale, M.D., Associate Professor of Ophthalmology at Harvard Medical School (HMS), and director of the HMS Glaucoma Center of Excellence and Mass. Eye and Ear Glaucoma Service and Telemedicine Service. “However, 80 percent of control individuals also harbor these variants and that ratio of cases to control individuals with trait-related variants is fairly similar in regions where XFS is very prevalent and in regions where the condition is relatively rare; this suggests that other genetic or environmental factors contribute to XFS.”