Abstract
Purpose: :
To estimate prevalence and severity of undetected glaucoma in the population.
Methods: :
A large screening investigation of individuals 55 - 79 years of age was performed to recruit for the Early Manifest Glaucoma Trial in Malmö, Sweden, between 1992 and 1997. All subjects in the screened age groups living in the catchment area, and for whom there we no records at our department, were invited. We registered age, gender and amount of visual field loss in previously undiagnosed patients identified at the screening. Visual field loss was categorized in to six different glaucoma stages based on mean deviation (MD) values using a simplified version of a published system for glaucoma stage classification described by Mills and coworkers in 2006.
Results: :
Among 32,918 screened subjects (77.5% of all invited) a total of 406 subjects (1.23%) were identified with previously undetected glaucoma. Prevalence increased with age, from 0.55% at 55-59 years, to 2.73%, in subjects between 75-79 years. Unilateral disease accounted for about two thirds of all cases. Extent of visual field loss was similar in all age groups. Most eyes had early (MD: -6 dB to 0 dB) 35%, or moderate glaucoma (MD -12 to -6.01 dB), 31%, but 134 subjects (33%) had at least one eye in the advanced (MD worse than -12 dB) or later stages. 29 patients (7%) had both eyes in these glaucoma stages. No subject was blind in both eyes, but 3.4% of the newly diagnosed patients were unilaterally blind in glaucoma.
Conclusions: :
Prevalence of undetected glaucoma increased with age, while disease severity did not. One third of subjects, had glaucoma in advanced or later stages. Unilaterally blind subjects were seen in all age groups.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • visual fields