Author response: prevalence of corneal dystrophies in the United States: estimates from claims data.

PURPOSE To estimate the prevalence of corneal dystrophies. METHODS Records of almost 8 million enrollees in a national managed-care network throughout the United States who had an eye care visit in 2001 to 2009 were searched for a recording of corneal dystrophy on a claim submitted by an ophthalmologist or optometrist from January 1, 2001, through December 31, 2007. RESULTS Unique individuals (n = 27,372) received two or more diagnoses of any type of corneal dystrophy, for an overall corneal dystrophy prevalence rate of 897 per million (10⁶) covered lives. Endothelial and anterior corneal dystrophies accounted for most of the reported dystrophies, and granular corneal dystrophy was the least common, being reported in 167 enrollees. Age, sex, and race variations among the various corneal dystrophies were observed. The mean age of those with macular corneal dystrophy (47.3 years) was 15 years younger than the age of those with endothelial dystrophy (62.9 years), and females were most highly represented (68.5%) among those with lattice corneal dystrophy. Hispanics and blacks were underrepresented relative to enrollees undergoing eye care for reasons other than corneal dystrophy. Keratoplasty was most frequently coded among those with lattice dystrophy. CONCLUSIONS Although caveats must be considered in using claims data to estimate prevalence in a population, these data provide an indication of corneal dystrophy's prevalence within insured subjects across the United States. Variations in age, sex, and race, within and between the different types of corneal dystrophies, raise questions that warrant further study.