Vitelliform dystrophies: Prevalence in Olmsted County, Minnesota, United States.

BACKGROUND: Vitelliform dystrophies are a group of macular degenerative diseases characterized by round yellow lesions in the macula. While often idiopathic, vitelliform dystrophies include inherited maculopathies such as Best disease and some cases of pattern dystrophy. The prevalence of vitelliform dystrophies in the United States has not been reported. This study examined the prevalence of vitelliform dystrophies in Olmsted County, Minnesota.

MATERIALS AND METHODS: The Rochester Epidemiology Project database was used to identify all cases of vitelliform or pattern dystrophy in Olmsted County from 1 January 2000-31 December 2014.

RESULTS: Overall, 27 patients had true vitelliform lesions, indicating a prevalence of 1 in 5500. Of these, two had genetically confirmed Best disease, and an additional five to seven carried a diagnosis of Best disease, which chart reviews confirmed as probable cases; 18-20 patients had adult-onset vitelliform macular dystrophy. The prevalence of Best disease was 1 in 16,500 to 1 in 21,000. Adult-onset vitelliform macular dystrophy was found in 1 in 7400 to 1 in 8200.

CONCLUSIONS: Vitelliform dystrophies affect 1 in 5500 individuals in Olmsted County. While the values in this study provide good estimates for the prevalence of Best disease versus adult-onset vitelliform macular dystrophy, the results are limited by dependence on diagnoses made by other ophthalmologists and underutilization of genetic testing. Thus, these diseases should be thought of as at least as prevalent as reported here. As therapies for Best disease and other macular degenerative diseases are quickly becoming a reality, genetic testing should be employed as the gold standard for diagnosis of these diseases.