Abstract
Purpose:
Despite the fact that glaucoma is the leading cause of blindness in African Americans (AA) in the United States, up to 75% of patients with glaucoma remain undetected. Ocular coherence tomography (OCT) has potential to detect glaucoma in the community setting, however there are no long-term trials proving its effectiveness. The purpose of this study is to project the effect of OCT screening and earlier treatment, on visual outcomes in AA patients.
Methods:
A Monte Carlo micro-simulation model was developed to evaluate the visual field impact and economic burden of community-based glaucoma screening, with 50,000 AA patients 50 years or older over a 10-year period. For the purposes of this model, we assumed a 60% follow up rate after failed screening.
Results:
The costs associated with screening 50,000 AAs with no prior diagnosis of glaucoma were approximately $98 per patient screened. When treatment was accounted for, costs rose to $795 for each patient screened over 10 years. In our model, screening decreased the prevalence of undiagnosed glaucoma from 75% to 38%. At 10 years, 6.1% fewer patients progressed to severe visual field loss and 14.8% more patients remained in the mild visual field loss when comparing screened versus not screened groups. The results of the model were subject to variability based on: age, initial visual field status, follow up rate, medication efficacy, and OCT test sensitivity and specificity. Increasing the follow up rate from 60% to 80% decreased the prevalence of severe visual field loss by 17.6% in the screened group compared the not screened group. This is an improvement of 9% when compared with 60% follow up rate.
Conclusions:
Our model shows that OCT screening is effective at reducing visual field loss, with a low cost per individual screened. OCT screening significantly reduced the number of undiagnosed cases of glaucoma in a high-risk population. Additionally, early identification and treatment significantly decreased the number of patients suffering from severe visual field loss at the 10-year time horizon and increased the number of patients maintaining mild visual field loss. This study supports the fact that follow up rate is an important modifiable factor to improve efficacy of screening and decrease morbidity associated with glaucoma.
Keywords: 758 visual fields •
460 clinical (human) or epidemiologic studies: health care delivery/economics/manpower