VKH Found in 5% of Uveitis Cases, More Common in Women

This study confirms that VKH disease exhibits geographical differences in expression, likely influenced by racial and ethnic susceptibility. Higher rates were found in Asian countries and Africa, and lower rates were found in North America, Europe and Oceania. Click image to enlarge. Vogt-Koyanagi-Harada (VKH) disease, a granulomatous autoimmune disorder, has been historically associated with specific ethnic groups with higher melanin counts, suggesting an underlying susceptibility. A new meta-analysis by a team of South American researchers looked at the global epidemiology of VKH to determine the distribution of disease in individuals presenting with uveitis. They found higher rates of VKH in Southeast Asia, East Asia and African, and lower rates in North America, Europe and Oceania. The findings were published in the British journal Eye.A total of 258 studies published between 2001 and 2025, spanning six continents and 44 countries, were analyzed.The estimated frequency of VKH among uveitis cases was 5.11% overall, with predominance of female patients. The frequency is higher in adults than in the pediatric population.  “Although participants’ racial or ethnic background was rarely reported, the observed geographic distribution aligns with regional demographic trends, supporting previous observations that VKH is more prevalent in populations from Asia and the Middle East, and less common in countries with predominantly European-descended populations,” the authors wrote in their paper. “These findings support the role that race and ethnicity play in the disease expression, which may reflect underlying pathogenic mechanisms, including autoimmune response against melanocytes and specific HLA- DR/DQ associations.”Interestingly, while VKH disease is often associated with Native-American and Mestizo populations, South America exhibited a relatively low frequency compared to Asian subregions and Africa. The continent’s weighted frequency was 3.77% in all studies, with 3.42 in the pediatric and 7.42% in the adult population. Notably, most studies from this region originated from Colombia, which reported the lowest weighted frequency in the region.“In contrast, Chile’s only study ranked ninth in overall VKH frequency among included studies,” the authors—from Chile, Argentina, Brazil and Columbia—wrote in their paper. “A similar pattern was observed in the other regions, such as Africa, where East African countries exhibited lower VKH prevalence compared to North Africa, a region with substantial Arab, Berber and Coptic populations. In Canada, First Nations populations exhibited significantly different outcomes than the general population. These findings may reflect intra-regional variations in VKH expression, potentially influenced by racial composition.”Potential explanations for gender differences include the influence of sex hormones on immune response and the presence of specific HLA-DR gene alleles restricted to the female gender, the team noted in their paper.  “Although VKH can affect all ages, it is less prevalent in the pediatric population,” they wrote. “In the present study, only 81 out of 169 studies provided data allowing stratification between the adult and pediatric populations, and just 34 included age-specific information. Nonetheless, the overall relative frequency of VKH among uveitis cases was higher in the adult population than in pediatric studies, suggesting a greater burden in adults.”Looking at shortcomings, the researchers noted the influences of methodological differences among the studies, potential publication bias (small studies with higher frequencies may be underrepresented) and geographical bias favoring the Global North, which should be considered when interpreting these findings.Overall, they concluded, the meta-analysis highlights the need for further epidemiological research, particularly in underrepresented regions, to better understand the global disease burden and improve healthcare resource allocation, the authors concluded in their paper.Click here for the journal source. Cholaky-Mejia NR, Abde-Celis MI, Pachon-Suarez DI, et al. Vogt-Koyanagi-Harada disease frequency around the globe: a systematic review and meta-analysis. Eye. June 12, 2026. [Epub ahead of print.] This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.