Abstract： AIM: To analyze the impacts of the shape of uveal melanoma on retinal structure.?METHODS: Histopathological sections and clinical data from patients with uveal melanoma were retrospectively observed and analyzed, and key indicators including the tumor ' s shape, size, height - to - base ratio, retinal thinning and retinal invasion were analyzed.?RESULTS: The study included 102 patients ( 102 eyes ) with a mean age of 45.6±12.4 years, with 76 (75％) uveal melanomas showing the spindle cell type, 6 ( 6％) showing the epitheloid cell type, 16 ( 16％) showing the mixed cell type and 4 ( 4％) showing predominantly other cell types. Differentiated by tumor locations: 3 cases of ciliary body melanoma ( 2. 9％) , 28 cases of ciliary body and choroid melanoma ( 27. 5％) , 71 cases of choroid melanoma ( 69. 6％) . Retinal thinning was detected in 43 ( 43％) eyes and retinal invasion by the tumor cells in 86 ( 84％) eyes. Maximal tumor height ranged between 1. 2 and 15.6 ( mean:8.3± 3.6) mm, and mean maximal tumor base diameter was 17.3± 6.5 ( range:4.8-31.2) mm. Mean R-value as ratio of tumor peak height to maximal tumor&nbsp;base diameter was 0. 53 ± 0. 32. Mean R - value was significantly higher in the group with retinal thinning ( n=43) than in the group without retinal thinning ( n=59) (0. 69±0.31 vs 0.42±0.27; P<0.01). R-value was slightly, however statistically not significantly higher in the group with retinal tumor invasion ( n=86 ) than without retinal tumor invasion (n=16) (0.56±0.33 vs 0.41±0.25;P=0. 09).?CONCLUSION: A high R-value indicating a prominent tumor is associated with tissue thinning in the adjacent retina, and marginally significantly with intra - retinal tumor cell invasion. Shape of uveal melanomas ' s corss section is of importance for the secondary involvement of the adjacent retina.