Author(s): J. Fernando Arevalo, MD FACS, Juan David Arias, MD

Purpose: To describe the vascular features of choroidal tumors using swept-sourceoptical coherence tomography (SS-OCT), and OCT-angiography (OCT-A).

Methods: In this prospective study, we evaluated 29 cases of intraocular tumors, including; 16 choroidal nevus, 6 choroidal melanomas, 4 choroidal hemangiomas and 3 choroidal metastasis. Patients underwent a complete ophthalmic examination including echography, OCT-angiography, multicolor imaging, fluorescein, and indocyanine angiography.

Results: SS-OCT for choroidal nevus demonstrates a small dome shape choroidal lesion, with smooth surface with choriocapillaris compression. Chronic retinal pigment epithelium (RPE) changes can be seen in association with drusen. In all cases, the choriocapillaris angiogram showed a hyperreflective lesion that correlates to the choroidal lesion in color fundus imaging. Choroidal melanoma, is seen in SS-OCT, as a smooth dome-shaped lesion with choriocapillaris compression. They produce overlying “shaggy” photoreceptors and may be associated with subretinal fluid (SRF). We found with OCT-A that the deep vascular plexus in melanomas is more heterogeneous than in choroidal nevi. By manual segmentation, melanoma appears as a hyporeflective lesion with capillary density decreasing centripetally. After treatment with transpupillary thermotherapy (TTT) the lesion persisted hyporeflective, but a substantial decrease in capillary density was observed. This may represent a decrease of intralesional vascularization that manifests with a tumor activity and size reduction. Choroidal hemangioma shows in SS-OCT as a smooth, sharp dome-shaped choroidal lesion with choriocapillaris infiltration. SRF and cystoid retinal changes could be present with expansion of small, medium, and large‐size choroidal vessels without compression. OCT-A reveals a heterogeneous lacy-like hypereflectivity with focal hyporeflective areas at the choriocapillaris angiogram. The capillary density is high which supports the fact of it is vascular in nature.  The hypereflective areas could correspond to expanded vascular interfaces without choriocapillaris compression.  The hyporeflective areas may represent low blood flow within dilated vessels inside the tumor. After treatment with TTT, a reduction in capillary density was observed predominantly at the edge of the lesion associated with SRF resolution and overlying retinal atrophy. This may represent an association of tumor activity control and hypoperfusion of lesion edges. Choroidal metastasis appears in SS-OCT as a choroidal lesion with a “lumpy, bumpy” surface without choriocapillaris compression. It presents usually with “shaggy” photoreceptors and SRF. OCT-A reveals a hyporeflective lesion on choriocapillaris angiogram with “cloud-like edges”. The capillary density is reduced and is accompanied by SRF visible on the deep retina angiogram. After TTT, an improvement of the internal blood flow is observed at the expense of large choroidal vessels with Haller’s layer and choriocapillaris atrophy. Subretinal fluid reabsorbs, and the overlying retinal atrophy is observed. 

Conclusions: OCT-angiography is a noninvasive reliable method with which to evaluate the vascularization of small choroidal tumors and may improve the diagnosis of these tumors.