Abstract
Purpose: :
To describe the optical characteristics of choroidal tumors using Enhanced Depth Imaging (EDI) Spectral Domain-OCT technique.
Methods: :
Prospective observational case series. All patients underwent clinical, fundus photography and ultrasonographic evaluation. EDI -OCT (Spectralis, Heidelberg, Germany) was performed using one or more 9.0 mm line section, in a 20º x 30º field with averaging of 100 frames. OCT acquisition and analysis used point to point correlation between the OCT and fundus images. Qualitative analysis consisted of assessing the status of choroidal layers, suprachoroidal space and detection of sclera. Quantitative data (maximal tumor thickness) was measured from the hyperreflective line corresponding to retinal pigmentary epithelium to inner sclera.
Results: :
A total of 23 cases of choroidal tumors were included (male, 12): nevus (13), melanoma (3), hemangioma (3) choroidal metastasis (4). In all cases, OCT was able to identify the tumor distinctly from the surrounding normal choroid. Qualitative analysis showed 1. Melanocytic lesions: hyperreflective band in choriocapillaris layer and posterior shadowing, 2. Amelanotic nevus: homogeneous and intermediate reflective band associated with visible choroidal vessels, 3. Hemangioma: hyporreflective and homogenous signal and 4. Metastatic tumors: hyporreflective band in deeper choroid causing enlargement of suprachoroidal space. Nine tumors (6 nevus / 3 metastasis), which were undetectable by USG, could be measured by OCT (mean thickness 583 µ; range 196µ-870µ). In the remainder cases tumor size could not be accurately assessed due to large diameter (> 9.0 mm) or thickness (> 1.00 mm).
Conclusions: :
It is possible to visualize choroidal tumors using EDI-OCT with cross-sectional view of the lesion. Tumors less than 1.00 mm in thickness can be measured objectively by OCT. Specific OCT characteristics for varied tumors do not allow precise differentiation between them.
Keywords: tumors • imaging/image analysis: clinical • oncology