Epidemiologic Relationship Between Fuchs Heterochromic Iridocyclitis and the United States Rubella Vaccination Program

Abstract

To investigate an epidemiologic association between Fuchs heterochromic iridocyclitis (FHI) and the rubella vaccination program in the United States. Observational case series. The percentages of patients with FHI, idiopathic chronic iridocyclitis, and idiopathic chronic granulomatous iridocyclitis at the University of Illinois were compared over time. Analysis of country of origin (United States vs foreign-born) was also performed. Findings were correlated with implementation of the rubella vaccination program in the United States in 1969. A total of 3,856 patients were seen between 1985 and 2005. Percentages of patients with FHI and idiopathic chronic granulomatous iridocyclitis born between 1919 and 1958 were similar (FHI 3.51% to 5.19%; idiopathic chronic granulomatous iridocyclitis 3.51% to 4.72%), with more variability in the idiopathic chronic iridocyclitis group (6.63% to 11.32%). A 64.8% reduction in FHI subjects was seen for those born the following decade (1959 to 1968). An additional 39.7% drop in FHI occurred in patients born between 1969 and 1978. Only one patient with FHI was born during the decade 1979 to 1988. The trend over time for FHI differed significantly from idiopathic chronic iridocyclitis (P = .0007) and idiopathic chronic granulomatous iridocyclitis (P = .0002), with no difference between the controls (P = .5437). The percentage of foreign-born patients with FHI increased after the institution of the rubella vaccination program (42% to 55%) compared with those born in previous decades (24% to 25%). This was not observed in the controls. FHI is less common in patients born since the introduction of the US rubella vaccination program, with a corresponding increase in percentage of foreign-born cases. This epidemiologic study supports a relationship between the rubella virus and FHI.