Retinal Vascular Patterns and Capillary Plexus Reflectivity of Intraocular Tumors; an Optical Coherence Tomography Angiography Study

Abstract

Purpose: To define the vascular characteristics of malignant and benign intraocular tumors by optical coherence tomography angiography (OCTA) and consequently to determine the advantages and disadvantages of the imaging technique in clinical practice.

Methods: This prospective, descriptive study consisted of choroidal hemangioma, choroidal nevus, choroidal melanoma, ocular melanocytoma, congenital hypertrophy of retinal pigment epithelium (CHRPE), and choroidal osteoma. Retinal angiography images were taken by OCTA in a 6 × 6 mm HD scan protocol. OCTA characteristics were defined by considering different tumor types separately.

Results: This study included 93 eyes of 90 patients diagnosed with benign or malignant intraocular tumors. The mean age of the patients was 48.9 ± 16.9 years in the hemangioma group, 55.3 ± 12.9 years in the nevus group, 48.2 ± 13.4 years in the melanoma group, 48 ± 18.9 years in the melanocytoma group, 45 ± 22.9 years in the CHRPE group, and 27.8 ± 7.8 years in the osteoma group. We showed four vascular patterns at the level of the choriocapillaris layer in circumscribed choroidal hemangiomas - the appearance of a "bag of worms," club-like appearance, giant choroidal vessels and normal choriocapillaris. The rates of these vascular patterns were 40%, 30%, 10%, and 20% in treatment-naïve hemangiomas and were 46.1%, 30.8%, 7.7%, and 15.4% in photodynamic therapy-treated hemangiomas, respectively. There was no different vascular structure in the tumor associated with the lesion in the nevus group. There were three different patterns at the choriocapillaris level in the melanomas - a vascular network (10%), avascular areas (30%) and vascular loops (60%). There were some atypical and nonspecific vascular changes demonstrated in the CHRPE and osteoma groups and a fine vascular network was observed in the melanocytoma group.

Conclusion: The different types of intraocular tumors had specific vascular characteristics which were easily demonstrated by the OCTA machine. This imaging technique can be a useful tool to differentiate these intraocular tumors non-invasively.

Keywords: Choriocapillaris; OCTA; en-face image; intraocular tumors; plexus reflectivity.