Prevalence of glaucoma. The Beaver Dam Eye Study.

PURPOSE

The purpose of this study is to determine the prevalence of glaucoma in the population participating in the Beaver Dam Eye Study (n = 4926).

METHODS

All subjects were examined according to standard protocols, which included applanation tonometry, examination of the anterior chamber, perimetry, grading of fundus photographs of the optic disc, and a medical history interview. Visual field, cup-to-disc ratio, and intraocular pressure (IOP) criteria were used to define the presence of open-angle glaucoma. Definite open-angle glaucoma was defined by the presence of any two or all three of the following: abnormal visual field, large or asymmetric cup-to-disc ratio, high IOP.

RESULTS

The overall prevalence of definite open-angle glaucoma was 2.1%. The prevalence increased with age from 0.9% in people 43 to 54 years of age to 4.7% in people 75 years of age or older. There was no significant effect of sex after adjusting for age. Of the 104 cases of definite open-angle glaucoma, 33 had IOPs less than 22 mmHg in the involved eye. Hemorrhage on the optic disc was found in 46 people; 2 of these had glaucoma. Narrow-angle glaucoma was rare, with two definite cases in the population.

CONCLUSION

The prevalence of open-angle glaucoma in Beaver Dam is similar to that in other white populations. Findings from this study re-emphasize the notion that estimates of glaucoma prevalence should be based on assessing multiple risk indicators.