According to a computer-based mathematical model in the March issue of the JAMA journal Archives of Ophthalmology, middle-aged African-American patients may benefit from a routine national glaucoma screening program. However, the test's potential effect on decreasing visual impairment and blindness could be small.
Background information in the study states:
"Primary open-angle glaucoma is a chronic, degenerative disease that affects more than 2.2 million Americans and 1.9 percent of Americans older than 40 years. The high prevalence of undiagnosed glaucoma contributes to visual loss, an outcome that is disproportionately common in African American individuals, where as many as 11 percent of elderly patients develop blindness."
Joseph A. Ladapo, M.D., Ph.D., previously at Beth Israel Deaconess Medical Center and Harvard Medical School in Boston who is now at the NYU Langone Medical Center in New York, and his team obtained data from the Eye Diseases Prevalence Research Group and Baltimore Eye Study to develop a micro-simulation computer-based model that projects visual outcomes amongst African Americans who receive glaucoma screening under a national screening policy.
The researchers model demonstrated that a universal, community-based glaucoma-screening program for African American patients could be clinically effective, even though the overall possible impact on the patients' visual impairment and blindness may be somewhat modest.
They predict that by screening African Americans aged between 50 to 59 years without diagnosed glaucoma, the outcome could result in a lower lifetime prevalence of undiagnosed glaucoma from 50% to 27%, and lower the prevalence of glaucoma-related visual impairment from 4.6% to 4.4%, as well as reducing the prevalence of glaucoma-linked blindness from 6.1% to 5.6%.
The researchers calculated the projected cost per screened individual as $80, which only includes the cost of frequency-doubling technology and an eye examination to confirm the diagnosis. They calculated that in order to diagnose one patient with glaucoma, 58 individuals would have to be screened, whilst estimating that 875 people would have to be screened in order to prevent one person from developing visual impairment.
The researchers point out that the estimations did not include "the cost of visual rehabilitation, disability or long-term care in patients with blindness, which are substantial." They summarize their findings, saying:
"We conclude that routine screening for glaucoma in African American individuals is a potentially clinically effective and economical method to reduce the burden of glaucoma-related visual impairment and blindness, though its absolute benefit is likely to be modest. Future studies should also consider long-term costs associated with treatment and the impact of delaying visual impairment on health-related quality of life."
Written by Grace Rattue