The Ocular Hypertension Treatment Study

Abstract

IN ALL SURVEYS, glaucoma is among the leading causes of blindness in the United States and other industrialized countries.^1-3 By the year 2000, it is estimated that 2.47 million people in the United States will have glaucoma and that more than 130,540 persons will be legally blind from the disease.⁴ Many more individuals will be visually handicapped by this disease.^5,6 Epidemiological studies have found that fewer than 50% of cases of visual field loss due to glaucoma have been diagnosed.^7-9 It is now clear that glaucoma is the leading cause of blindness in African Americans.^2,10,11 In the Baltimore Eye Survey, the age-adjusted prevalence rates of primary open angle glaucoma (POAG) were 4 to 5 times higher in African Americans than in whites, ranging from 1.2% in African Americans aged 40 through 49 years to 11.3% in those 80 years or older.¹² The Barbados Eye Study in a Carribean population of African origin confirmed the high prevalence of glaucoma in such populations.⁷ The 4-year incidence rate of POAG in this population was 2.2% overall and 5.8% among persons with ocular hypertension,¹³ which is more than 5 times higher than the estimated incidence in a predominantly white population.¹⁴