Population-based incidence of intraocular tumours in Olmsted County, Minnesota

Background/aims To determine population-based incidence of intraocular tumours in Olmsted County, Minnesota. Methods Record review of the Rochester Epidemiology Project medical record linkage system from 1 January 2006 to 31 December 2015 for patient demographics, tumour type by clinical diagnosis and presence or absence of confirmation by histopathology. The incidence rate of any intraocular tumour and of each tumour type was calculated per million person-years. Poisson regression analysis was used to analyse changes in incidence over time. Results There were 948 patients diagnosed with intraocular tumours resulting in an age-adjusted and sex-adjusted incidence rate of 727.5 per million (95% CI: 680.8 to 774.2, p<0.05). Most tumours were benign (953, 98%). Of the benign lesions, melanocytic lesions were the majority (942, 97%), with adjusted incidence rates of 646.9 (95% CI: 602.8 to 691.1) for choroidal nevus and 55.8 (95% CI: 43.2 to 64.8) for iris nevus. Malignant lesions were rare (16, 2%) with 13 cases of choroidal melanoma and 1 case each of iris melanoma, retinal leukaemic infiltration and metastasis. The adjusted incidence rate for choroidal melanoma was 7.1 (95% CI: 2.5 to 11.8). Conclusion In a population-based setting, most intraocular tumours are benign and melanocytic. Although malignant lesions are less common, it is important to remain vigilant with appropriate monitoring given the potential for vision loss and life-threatening malignancy.