Objective: To determine the incidence of ulcerative keratitis and to assess trends in risk factors leading to ulcerative keratitis.
Design: Retrospective incidence cohort study.
Setting: General community.
Patients: Population-based sample of residents of Olmsted County, Minnesota, in the 39-year period between 1950 and 1988.
Main outcome measure: Cases of ulcerative keratitis.
Results: One hundred forty-one cases of ulcerative keratitis were diagnosed among 131 residents (64 men and 67 women) of Olmsted County. The mean annual age-adjusted incidence per 100,000 people was 5.3 (95% confidence interval, 4.4 to 6.2). A 435% increase in the incidence of ulcerative keratitis was observed in Olmsted County residents from the 1950s (2.5 per 100,000 people) to the 1980s (11.0 per 100,000 people) (P = .001). The cases of ulcerative keratitis associated with contact lens wear increased from 0% in the 1950s and 1960s to 32% in the 1970s and 52% in the 1980s.
Conclusion: The incidence of ulcerative keratitis has increased significantly in this community. Contact lens wear was the most important risk factor for the development of ulcerative keratitis during the last decade.