exfoliation glaucoma (EG) is the leading cause of secondary
open-angle glaucoma worldwide.1 In EG, disarrayed extracellular
deposits and admixed pigment lodge in the trabecular
meshwork to produce elevated intraocular pressure (IOP) and
optic neuropathy. An association between the lysyl oxidase like
1 (LOXL1) gene variants and exfoliation syndrome (ES) was
discovered in Iceland where the disease burden is very high2;
yet the prevalence of LOXL1 polymorphisms from Scandinavian
countries is similar to that of other countries with widely
varying disease prevalence.3–10 While genetic variants other
than LOXL1 polymorphisms might contribute to ES and EG,11
these data suggest that environmental factors could also play a
role in this syndrome. Established risk factors for ES and EG
includes older age12,13 and female sex.12–14 Recent studies also
indicate that relative to living in the middle or southern United
States, residing in the northern tier of the continental United
States is associated with increased risk of ES and EG.14,15 Only
sparse data are available for other modifiable risk factors for ES
and EG.16