Majority of glaucoma cases go undiagnosed in the United States
Glaucoma is one of the leading causes of blindness in the United States, especially among the elderly. This is a common, asymptomatic group of eye diseases that damage the optic nerve in the eye, resulting in progressive and irreversible vision loss. As the disease is asymptomatic in the early stages and progresses slowly, most cases go undiagnosed. The burden of glaucoma is expected to increase in the near future due to the increasing aging of the population, especially if the diagnosis rate remains low.
Primary open-angle glaucoma (POAG) accounts for nearly 90% of glaucoma cases. GlobalData epidemiologists predict that the total number of prevalent cases (diagnosed and undiagnosed) of POAG in the United States will increase at an annual growth rate (AGR) of 2.8% per year over the next ten years, rising from ‘about 3.6 million cases last year to 4.6 million cases. in 2030 (Figure 1). Prevalent cases diagnosed, however, represent less than half of the total cases, with around 1.6 million prevalent cases diagnosed last year and two million prevalent cases diagnosed in 2030. Various studies in the United States have reported that glaucoma diagnosis rate is 30–50% of total cases.
According to a February 2016 study conducted by Gupta and colleagues and published in the journal Investigative Ophthalmology and Visual Science, approximately 43.7% of cases in the survey were diagnosed with glaucoma by a doctor. The study used data from the National Health and Nutrition Examination Survey 2005-08, a nationally representative survey of the American population. The burden of undiagnosed and untreated cases was also unevenly distributed across the American population. Undiagnosed glaucoma cases were higher in African Americans compared to the white population, while undiagnosed and untreated cases were also higher in the lower socioeconomic group. Additionally, comorbid conditions such as diabetes and high blood pressure have been shown to be major factors that increase the risk and complications of glaucoma. In the United States, diabetes and high blood pressure are widespread and are expected to increase further over the next several years. As such, epidemiologists at GlobalData believe the number of glaucoma cases will continue to rise, and the share of undiagnosed cases is unlikely to decline in the near future.
Glaucoma is a debilitating disease in terms of its impact on quality of life and of both progressive and irreversible deterioration of vision. When diagnosed early, however, the disease is manageable and prevents further deterioration of vision. Regular screening is necessary, especially in adults aged 40 and over, to detect signs of glaucoma earlier. Adapting public health policy for early diagnosis and treatment to the high-risk population will help reduce the burden of this disease.