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 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.