Abstract
Purpose:
To determine whether measures of intraocular pressure (IOP) variation are associated with the development of open-angle glaucoma (OAG) in an adult Latino population.
Methods:
The Los Angeles Latino Eye Study is a population-based, prospective cohort study of self-identified, 40+ years old Mexican Americans residing in Los Angeles, California. For the current analysis, a total of 3,666 study participants who were free of OAG at the study baseline and had completed four-year follow-up clinical examinations were included. Similarly designed interviews and comprehensive ophthalmologic examinations were conducted at both the baseline and the follow-up. OAG was defined as the presence of an open angle and a glaucomatous visual field abnormality and/or evidence of glaucomatous optic nerve damage in at least one eye. Four different measures (mean, peak, standard deviation, and range) of inter-visit IOP were derived from six IOP readings obtained at the baseline visit and the four-year follow-up visit. Multivariate logistic regression was performed to assess the association between the four measures of inter-visit IOP and the risk of developing OAG in four years.
Results:
Among the four measures of inter-visit IOP, peak inter-visit IOP was the best independent predictor of the incidence of OAG. Further examination revealed that the association between inter-visit IOP measures and incidence of OAG varied for individuals with different levels of IOP. Among participants with low mean IOP (≤18 mmHg), higher levels of peak, standard deviation, and range of inter-visit IOP were all significantly associated with a higher risk of developing OAG (P<0.05), while mean IOP were not associated with risk of developing OAG. Among participants with high mean IOP (>18 mmHg), higher levels of mean and peak of inter-visit IOP were significantly associated with higher risk of developing OAG, while standard deviation and range of inter-visit IOP were not associated with risk of developing OAG with or without adjustment for mean IOP. Results were similar when participants were grouped according to mean IOP <15 and ≥15 mmHg.
Conclusions:
Overall, peak inter-visit IOP was the best predictor of the incidence of OAG. Greater variation in IOP was associated with a higher risk of developing OAG among individuals with low mean IOP, but not among individuals with high mean IOP.
Keywords: 568 intraocular pressure •
464 clinical (human) or epidemiologic studies: risk factor assessment