Retinal vascular alterations associated with dome-shaped and mushroom-shaped choroidal melanomas

Purpose: Retinal vascular abnormalities are associated with choroidal melanoma. Although tumor ischemia, resulting in soluble angiogenic factor production, is a proposed etiology of these abnormalities, other sources of ischemia may also contribute. Mushroom-shaped choroidal melanomas have increased loss of the overlying choriocapillaris and increased subretinal fluid when compared to dome-shaped tumors; factors that may result in outer retinal ischemia, angiogenic factor production and resultant retinal vascular abnormalities. The differing amounts of retinal vascular abnormalities overlying dome-shaped compared to mushroom-shaped melanomas were determined to evaluate this hypothesis. Methods: Retinal vascular abnormalities observed on fluorescein angiograms of eyes with choroidal melanoma were compared to the tumor configuration and presence of subretinal fluid. Results: 23 eyes of 22 patients were included in the study. Retinal vascular abnormalities observed included dilated capillaries, telangiectatic capillaries, capillary nonperfusion, microaneurysms, neovascularization, lipid exudation and late staining of dye within the retina. Retinal vascular abnormalities were present in 4 of 14 eyes with dome-shaped tumors (29%) and in 8 of 9 eyes with mushroom-shaped tumors (89%). (Fisher's Exact Test, p=0.009). Retinal vascular abnormalities were present in 2 of 10 eyes without subretinal fluid (20%) and in 10 of 13 eyes with subretinal fluid (77%). (Fisher's Exact Test, p = 0.012). Conclusions: Retinal vascular abnormalities are associated with mushroom-shaped choroidal melanomas more commonly than dome-shaped tumors. Outer retinal ischemia may result from choriocapillaris loss or the presence of subretinal fluid, contributing to soluble angiogenic factor production and resultant retinal vascular abnormalities in these eyes. Summary statement: Retinal vascular abnormalities are associated with mushroom-shaped choroidal melanomas more commonly than dome-shaped tumors. These retinal vascular abnormalities may be related to an increase in outer retinal ischemia associated with mushroom-shaped tumors.