Association of demographic, familial, medical, and ocular factors with intraocular pressure

Objective: To describe the distribution and associations of demographic, fa milial, medical, and ocular factors with intraocular pressure (IOP). Methods: A cluster stratified random sample of urban and rural residents of Victoria, Australia, aged 40 years and older. Participants completed an in terview and underwent a standardized dilated ophthalmic examination includi ng measurement of IOP with an electronic applanation tonometer (Tono-Pen). Glaucoma status (possible, probable, definite) was determined by a consensu s panel. The main outcome measure was IOP. Results: The mean age of the 4576 participants was 59 years, 53% were women , 32% were born overseas, and 132 had open-angle glaucoma. Geometric mean ( SD) IOP was 14.3 (+/-1.5) mm Hg. The relationship between IOP and nuclear s clerosis, iris color, and family history of glaucoma depended on glaucoma s tatus. In those with glaucoma, family history of glaucoma and country of bi rth were significantly associated with IOP in multivariate models (model: r (2)=0.08, P=.01). In the group without glaucoma, place of residence, use of alcohol, iris color, vitamin E intake, and spherical equivalent were assoc iated with IOP (model: r(2)=0.01, P=.006). Conclusion: In participants with glaucoma, genetic factors seem to be stron ger predictors of IOP, whereas in those without glaucoma, lifestyle and phy siological. factors seem to play a greater role.