ObjectiveTo detect the level of serum melanoma-inbibiting activity (MIA) in patients with uveal melanomas, and investigate the value of MIA in diagnosing and inspecting uveal melanomas.MethodsEnzyme-linked immunosorbent assay (ELISA) was used to detect the concentrations of MIA in peripheral serum of 27 patients with uveal melanoma, 6 with melanocyte tumor, 7 with other ocular tumors and 16 healthy individuals, respectively.ResultsThe concentration of MIA in patients with uveal melanoma was significantly higher than that in the healthy ones (16 individuals) and the patients with adenoma of non pigmented ciliary epithelium (4 patients), retinoblastoma (2 patients), and retinal angioma 91 patient). The concnetration of MIA in patients with uveal melanoma without scleral infiltration or remote metastasis was obviously lower than that in the patients with scleral infiltration or remote metastasis, but didn′t differ much from which in the patients with melanocyte tumor. In the patients with uveal melanoma without infiltration or remote metastasis, there was no significant difference of MIA level between patients with spindle cell and mixed and epithelioid cell.ConclusionThe level of serum MIA may be an effective index in diagnosing uveal melanoma, which can monitor the metastasis of uveal melanoma.(Chin J Ocul Fundus Dis, 2005,21:153-155)