Distribution of intraocular pressure in a Swedish population

Increased intraocular pressure (IOP) and pseudoexfoliation (PEX) are major risk factors for open-angle glaucoma (OAG), an age-related neurodegenerative disease of significant importance for public health. There are few studies on the distribution of IOP in populations where PEX is a common finding.

The distribution of IOP was studied in 733 subjects 65-74 years of age, examined in a population survey in the rural district of Tierp, Sweden, 1984-86. The difference between the right and left eye and the effect of which eye was measured first were examined. Odds ratios, adjusted for age and sex, according to Mantel-Haenszel (OR_MH), were calculated to estimate predictors of increased IOP, defined as a pressure ≥20 mm Hg in either eye. The pressure was measured with Goldmann applanation tonometry. Automated perimetry was used to identify OAG.

The distribution of IOP was close to that of other European-derived populations. The pressure in the first measured eye was higher than in the second measured eye. Increased IOP was related to OAG and PEX, OR_MH 8.97 (95% confidence interval [CI] 3.84-20.9) and 2.40 (95% CI 1.53-3.76), respectively. An IOP ≥20 mm Hg increased the risk of having been diagnosed with diabetes (OR_MH 1.83; 95% CI 1.08-3.09).

In this study of subjects 65-74-years-old in Sweden, the distribution of IOP was close to that of other European-derived populations. Although the difference was small, the pressure in the first measured eye was higher than in the second eye. Increased IOP was strongly related to untreated OAG and PEX.