Projected Clinical Outcomes of Glaucoma Screening in African American Individuals

Objectives: To project the clinical impact of routine glaucoma screening on visual outcomes in middle-aged African American individuals and help guide glaucoma screening policy. Methods: Using data from the Eye Diseases Prevalence Research Group and Baltimore Eye Study, we developed a microsimulation model to project visual outcomes in African American individuals screened for glaucoma under a national screening policy using frequency-doubling technology. We projected the impact of universal screening on glaucoma-related visual impairment (acuity worse than 20/40 but better than 20/200 in the better-seeing eye) and blindness (acuity 20/200 or worse in the better-seeing eye). The diagnostic characteristics of frequency-doubling technology and the hazard ratio for glaucoma progression in treated patients were informed by meta-analyses of randomized controlled trials. Results: Implementation of a national glaucoma screening policy for a cohort of African American individuals between the ages of 50 and 59 years without known glaucoma would reduce the lifetime prevalence of undiagnosed glaucoma from 50% to 27%, the prevalence of glaucoma- related visual impairment from 4.6% to 4.4% (4.1% relative decrease), and the prevalence of glaucoma-related blindness from 6.1% to 5.6% (7.1% relative decrease). We project the cost of the program to be $80 per screened individual, considering only the cost of frequency-doubling technology and confirmatory eye examinations. The number needed to screen to diagnose 1 person with glaucoma is 58. The number needed to screen to prevent 1 person from developing visual impairment is 875. Conclusions: Routine glaucoma screening for middle-aged African American individuals is potentially clinically effective but its impact on visual impairment and blindness may be modest. However, we did not assess the impact on visual field loss.