A 75-year-old Asian man presented with blurred vision and metamorphopsia in the left eye. Fluorescein angiography and indocyanine green angiography revealed round mottled hyperfluorescence corresponding to the choroidal hemangioma at the temporal macula and a focal hyperfluorescent portion corresponding to a macular neovascular lesion at the subfovea. Swept-source optical coherence tomography showed shallow subretinal fluid at the macula and a dome-shape choroidal lesion occupying the choroidal hemangioma. En face optical coherence tomography angiography showed abnormal type 1 macular neovascularization comparable to a skein of thread at the level of the outer retina slab.
Secondary macular neovascularization may develop at the border of a choroidal hemangioma. This report presents a case of type 1 macular neovascularization arising from the border of a choroidal hemangioma detected using optical coherence tomography angiography.