Traumatic hyphema in a defined population.

From 1960 through 1984, traumatic hyphema was diagnosed in 248 residents (204 males and 44 females) of Olmsted County, Minnesota. The mean annual incidence rate was significantly greater (P less than .001) among males than among females: 20.2 per 100,000 population and 4.1 per 100,000, respectively. The overall mean annual rate was 12.2. A significant increase in the incidence rate in recent years was caused primarily by an increase in the number of sports-related injuries. Secondary hemorrhage occurred in 18 patients (7.3%) and was significantly (P less than .05) more frequent among patients whose initial hyphema filled more than one third of the anterior chamber. The low risk of secondary hemorrhage and associated serious sequelae suggests that the possible benefits from routine systemic administration of aminocaproic acid may not outweigh the costs and risks in populations similar to that of Olmsted County.