Australian study provides more evidence that genetics play a role in acute anterior uveitis

This prospective study reports the incidence and patterns of acute anterior uveitis (AAU) in central Australian Aboriginal and non-Aboriginal patients. The results contribute to the growing evidence implicating genetic factors in the pathogenesis of the disease.

The study includes all 1,955 patients seen over an eight-month period by the Central Australian Ophthalmology service, the only ophthalmology care provider servicing the Alice Springs area and surrounding remote Central Australia communities. The service diagnosed 11 AAU episodes in 10 patients. The researchers used this data to calculate an annual AAU rate for Central Australia of 35.9 cases per 100,000 population. This rate is similar to other geographic regions.

Although 42 percent of patients seen by the ophthalmology service during the study period were Australian Aboriginal, only one of the 10 AAU patients was Aboriginal. However, this patient reported having two Caucasian grandparents. The difference in AAU incidence between the indigenous and nonindigenous populations was statistically significant.

The gene HLA-B27 is the strongest known genetic risk factor for the development of AAU. Four of the nine Caucasian AAU patients indeed were HLA-B27 positive. The frequency of HLA-B27 among Aboriginals is unknown, but the one Aboriginal patient did carry the gene. It will be interesting to see whether further studies reveal that the low frequency of AAU in Aboriginals is related to their having a different HLA-B27 subtype or a lower frequency of HLA-B27 than populations with higher AAU rates.