Ocular melanoma may be more prevalent among patients with light irises than those with dark irises.
To examine a large clinical series of patients with intraocular melanoma to determine if light irises are associated with increased risk of death from these tumors.
A total of 1162 patients treated with proton irradiation between 1984 and 1996 were observed through 1997.
Iris color in the patients was blue or gray in 48%, green or hazel in 30%, and brown in 23%. Tumors in patients with blue or gray irises were less heavily pigmented (P<.001) and closer to the optic disc and macula (P<.001). Five- and 10-year metastasis-related death rates were 0.14 and 0.21, respectively, for those with blue or gray irises and 0.10 and 0.15, respectively, for those with darker irises (P=.02). In a Cox proportional hazards regression controlling for tumor characteristics, patients with blue or gray irises died of metastatic disease at a rate 1.90 times (95% confidence interval, 1.26-2.85) that of patients with brown irises. The rate of metastatic death was not significantly elevated for those with green or hazel irises (relative risk, 1.43; 95% confidence interval, 0.91-2.23).
Patients with blue or gray irises appear to be at increased risk of metastatic death from choroidal melanoma, independent of other risk factors.