Abstract
Purpose :
Organophophates are potent inhibitors of acetylcholinesterase. Echothiophate, an irreversible inhibitor of both acetylcholinesterase and pseudocholinesterase, has been used in the past to treat glaucoma due to its effect of increasing aqueous humor outflow facility. Many people are exposed to organophosphates due to their use as commercial insecticides. It is possible that environmental exposure to organophosphates may protect from glaucoma. This cross-sectional study tested the hypothesis that exposure to organophosphates is associated with a decreased risk of glaucoma.
Methods :
Data were extracted from the Laboratory and Examination databases of the National Health and Nutrition Examination Study (NHANES) 2007-2008. Participants were included if data was available on exposure to organophosphates and gradable optic nerve photographs. Exposure to organophosphates was considered positive for subjects with detectable levels of Dialkyl Phosphate metabolites in their urine. The presence of glaucoma was determined by a consensus of three glaucoma specialists grading optic nerve photographs as “Probable Glaucoma” or “Definite Glaucoma” according to the NHANES protocol. Subjects whose optic nerve photographs were graded as “No Glaucoma” or “Possible Glaucoma” were coded as not having glaucoma.
Results :
Inclusion criteria were met by 156 participants who had laboratory data and gradable optic nerve photographs available. Of these 69 (44.2%) had glaucoma and 87 (55.8%) did not have glaucoma. 137 (87.8%) were exposed and 19 (12.2%) were not exposed. Of those exposed, 62 (45.3%) had glaucoma and 75 (54.7%) did not. Of those without exposure, 7 (36.8%) had glaucoma and 12 (63.2%) did not. This resulted in an odds ratio (OR) of 0.99 (95% confidence interval (CI) 0.60 to 1.61, p = 0.9545).
Conclusions :
In NHANES participants, no positive or negative association between exposure to organophosphates and glaucoma was demonstrated. These results should be interpreted with caution since causation cannot be inferred from a cross-sectional study. However, despite the relatively small sample size, the study was sufficiently powered to detect a significant effect if one existed.
This is a 2020 ARVO Annual Meeting abstract.