Exudative retinal detachment from malignant uveal melanoma: predictors and prognostic significance.

PURPOSE: To determine independent predictors of exudative retinal detachment (RD) in eyes with uveal melanoma and the significance of RD in melanoma-specific survival.
METHODS: The extent of exudative RD was recorded retrospectively in a population-based cohort of 167 consecutive patients with eyes enucleated from 1972 through 1981 because of choroidal and ciliary body melanoma, representing all melanomas treated during that period. Histopathologic features including microvascular loops and networks, microvascular density (MVD), and tumor-infiltrating macrophages were determined. Clinical and histologic predictors of RD were modeled by multiple logistic regression with a split-sample, cross-validation design. Survival was assessed by Kaplan-Meier analysis and adjusted for the effect of competing predictors by Cox proportional hazards regression.
RESULTS: Of 142 (85%) eyes with adequate data, 25% had no RD, 16% had subretinal fluid around the tumor, 43% had clinical RD in one to two quadrants, and 16% had RD in three to four quadrants. The RD was more extensive if the tumor was large (P < 0.0001) and had microvascular loops and networks (P = 0.0094) and less extensive if it involved ciliary body (P = 0.011). High MVD (P = 0.054) and ruptured Bruch's membrane (P = 0.065) tended to be associated with RD. Multiple logistic regression showed largest basal diameter (odds ratio [OR] 1.43 for each 1-mm change, P < 0.0001), microvascular loops and networks (OR 1.95 for each category change, P = 0.0095), and ciliary body involvement (OR 0.20, P = 0.0039) to be independently associated with RD; ruptured Bruch's membrane (P = 0.96) and MVD (P = 0.87) were not associated. Clinical RD predicted poor survival (0.59 vs. 0.37 at 20 years; P = 0.029) by Kaplan-Meier analysis, but not after adjusting for other prognostic factors by Cox regression (hazard ratio [HR] 1.00, P = 1.0).
CONCLUSIONS: Tumor size, which may be a surrogate measure for total vascular content and decompensation of choriocapillaris and retinal pigment epithelium, is a strong predictor of exudative RD. Microvascular loops and networks are likewise associated with exudative RD. Exudative RD is not associated with survival after adjusting for tumor size and microvascular loops and networks.