Spectral-Domain Optical Coherence Tomography Versus Ultrasound Biomicroscopy for Imaging of Nonpigmented Iris Tumors

PurposeTo evaluate the use of spectral-domain optical coherence tomography (SDOCT) for imaging of nonpigmented iris tumors, through its comparison with ultrasound biomicroscopy (UBM).DesignRetrospective observational case series.MethodsConsecutive patients with non-pigmented iris tumors, not extending to the ciliary body, who were concurrently evaluated with SD-OCT and UBM were included. Demographics, anterior segment clinical photographs, images obtained with SD-OCT (Cirrus HD-OCT, Zeiss Meditec, Dublin, California, USA) with 5.1.1 anterior segment software upgrade, and UBM (Humphrey Instruments, San Leandro, California, USA) were reviewed. The images produced were compared regarding the degree of anterior and posterior tumor surface resolution, internal structures, tumor thickness measurement, image artefacts, and overall tumor visualization.ResultsThirty-seven patients with nonpigmented iris tumors were included. Comparing SDOCT to UBM, the image definitions of anterior tumor surface and internal tumor heterogeneity were equivalent. Posterior tumor surface was well defined in 54% of SDOCT vs 100% in UBM images. Full tumor thickness measurement was possible in 86% of SDOCT vs 100% with UBM. The maximum measurable tumor thickness with SDOCT was 1.34 mm. SDOCT images showed optical aberrations such as shadowing and ghost images in 22 tumors (59%), which encroached on the tumor image in 8 patients (22%). The overall tumor visualization with SDOCT was possible in 65% of the iris tumors.ConclusionsUBM generally provides superior imaging quality and reproducible measurements of nonpigmented iris tumors. Nevertheless, SDOCT, being a noncontact technique, can be a reliable alternative in imaging and following some selected nonpigmented iris tumors.