Study links decline in Fuchs' heterochromic iridocyclitis to rubella vaccination

The incidence of Fuchs' heterochromic iridocyclitis has significantly decreased among the U.S. population since the introduction of the rubella vaccination program, a study by researchers in Chicago shows. The finding supports a relationship between the rubella virus and the disease, the study authors noted.

Andrea D. Birnbaum, MD, PhD, and colleagues at the University of Illinois, along with centers in Israel and Virginia, compared the incidence of Fuchs' heterochromic iridocyclitis (FHI) cases seen at the University of Illinois Eye and Ear Infirmary over several decades. They also compared rates of FHI with the rates of idiopathic chronic iridocyclitis and idiopathic chronic granulomatous iridocyclitis (control groups) seen during the same time periods.

The researchers stratified patients according to the time period in which they were born: 1919 to 1958; 1959 to 1968; 1969 to 1978; or 1979 to 1988.

The study population included 3,856 patients seen at the center between 1985 and 2005.

"Percentages of patients with FHI and idiopathic chronic granulomatous iridocyclitis born between 1919 and 1958 were similar," the authors wrote.

Among those born between 1919 and 1958, 3.51% to 5.19% had FHI and 3.51% to 4.72% had idiopathic chronic granulomatous iridocyclitis. Idiopathic chronic iridocyclitis showed more variability and was seen in 6.63% to 11.32% of patients, according to the study.

The researchers found that the incidence of FHI decreased 64.8% among patients born between 1959 and 1968 and decreased another 39.7% among those born between 1969 and 1978, the authors reported.

The United States instituted its rubella vaccination program in 1969, they noted.

Only one patient born between 1979 and 1988 was seen with FHI, they added.

This trend for FHI differed significantly from idiopathic chronic iridocyclitis (P = .0007) and idiopathic chronic granulomatous iridocyclitis (P = .0002). The incidence of these two diseases remained relatively consistent over time, according to the study.

In contrast, the incidence of FHI among foreign-born patients has increased since the introduction of the rubella vaccination program. Before the vaccination program, FHI was seen in 24% to 25% of foreign-born patients, which increased to range from 42% to 55% after the program's start.

"This was not observed in the controls," the authors said.

The study is published in the September issue of American Journal of Ophthalmology.