Role of optical coherence tomography in verifying the specificity of ultrasonography in detecting subtle subretinal fluid associated with small choroidal melanocytic tumors.

PURPOSE: To report the use of optical coherence tomography (OCT) in verifying the specificity of the ultrasonographic "apical double echo" sign in detecting subtle subretinal fluid (SRF) associated with small choroidal melanocytic tumors. METHODS: Retrospective review of consecutive patients demonstrating ultrasonographic "apical double echo," indicative of subtle SRF, who concurrently underwent OCT on initial evaluation of untreated small choroidal melanocytic tumors. Ultrasonography was performed with eyecubed version 3, ophthalmic ultrasound system (Ellex/Innovative Imaging, Inc, Adelaide, Australia) and OCT with spectral-domain OCT, Cirrus HD-OCT, model 4000 (Carl Zeiss; Meditec, Dublin, CA). Optical coherence tomographic images were examined to verify the presence of SRF and to identify other retinal pathology producing apical double echo in the absence of SRF. RESULTS: The study included 36 patients. With OCT, subtle SRF was present at tumor apex and/or margins in 20 patients (55%) and absent in 16 patients (45%). When SRF was present, it was detected at tumor apex only in 3 of 20 patients (14%), gravitated at the inferior margin only in 13 of 20 patients (64%), and at apex and inferior margin in 4 of 20 patients (22%). When SRF was absent, the retina over the tumor showed degenerative cystic changes in 10 of 16 patients (65%), retinal thickening in 4 of 16 patients (25%), and retinal pigment epithelium detachment in 2 of 16 patients (10%), accounting for the ultrasonographic apical double echo. CONCLUSION: Ultrasonography showed limited specificity for detecting subtle SRF related to small choroidal melanocytic tumors, with 45% of patients showing ultrasonographic apical double echo in the absence of SRF with OCT. The retinal changes that yielded false-positive results included retinal cystic degenerations, retinal thickening, and retinal pigment epithelium detachment. Optical coherence tomography is preferred to verify the presence of subtle SRF over small choroidal melanocytic tumors, provided that the inferior tumor margin is included in imaging.

Spectral-domain optical coherence tomography versus ultrasound biomicroscopy for imaging of nonpigmented iris tumors.

PURPOSE: To evaluate the use of spectral-domain optical coherence tomography (SDOCT) for imaging of nonpigmented iris tumors, through its comparison with ultrasound biomicroscopy (UBM). DESIGN: Retrospective observational case series. METHODS: Consecutive 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. RESULTS: Thirty-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. CONCLUSIONS: UBM 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.