Purpose: To study the effect of potential risk factors on the development of open-angle glaucoma (OAG) in a population in which pseudoexfoliation (PEX) is a common finding.
Methods: In 1984-1986, a population-based survey of 760 people aged 65-74 years was conducted in the municipality of Tierp, Sweden. From 1988 to 2006, a follow-up study of the 530 people with normal visual fields has been in progress. To increase the cohort, 273 ophthalmic outpatients were enroled. Reliable visual fields were available for 679 people, representing 6 126 person-years at risk. A time-weighted mean intraocular pressure (IOP) for all visits was calculated.
Results: Sixty-four subjects developed definite OAG, 29 of whom were exposed to PEX. Risk factors associated with OAG were higher age, a positive family history, increased IOP and PEX. The age-standardized rate ratio (SRR) was 14.8 times (95% confidence interval [CI] 7.92-27.8) greater in subjects with mean IOP >/=20 mmHg than in those with mean IOP /=20 mmHg.
Conclusion: Increased IOP and PEX were serious risk factors for incident OAG. The effect of PEX was mediated by increased IOP.