and showed more circumferential spread in ciliary body (Po0.001) and iris (P ¼ 0.003). Tumours in men were more likely to extend to within 3 mm of optic disc or fovea (46.3 vs 39.0%, Po0.001), showing more extensive optic-disc involvement (Po0.001). The median largest basal tumour diameter was 12.2 mm in men and 11.9 mm in women (P ¼ 0.001). The tumour thickness had a median of 4.4 mm and 3.8 mm in men and women, respectively (P ¼ 0.015). The 180 ciliary body tumours occurred in 112 women and 68 men. In these, the prevalence of extraocular spread was higher in women (19.6 vs 8.8%; P ¼ 0.052). The 175 iris melanomas were more common in women than men (103 vs 72, respectively). Conclusions In men, UMs tend to be larger and more posterior than in women
