Purpose: To compare the sensitivity of commonly used time-domain (TD-OCT) and spectral-domain optical coherence tomography platforms and scanning modalities in the management of neovascular age-related macular degeneration in a population with a high prevalence of exudative disease activity.
Methods: Fifty consecutive patients within the prospective SAVE (Super-dose Anti-Vascular Endothelial growth factor) trial, which analyzed the utility of 2.0 mg intravitreal ranibizumab for the treatment of recalcitrant neovascular age-related macular degeneration, were enrolled in a comparison trial of 3 different optical coherence tomography (OCT) platforms. Stratus TD-OCT radial scan (Carl Zeiss Meditec, Inc) was compared with 3 Heidelberg Spectralis Heidelberg Retinal Angiograph+OCT (Heidelberg Engineering) acquisition settings (radial, 7-line raster, volumetric) and 2 Cirrus high definition (HD)-OCT (Carl Zeiss Meditec, Inc) acquisition settings (5-line raster, volumetric).
Results: Using every imaging platform and acquisition setting, evidence of exudative disease activity was positively identified in 163 of 191 patient visits (85.3%). Intraretinal cysts were identified in 83 of 191 visits (43.5%), and subretinal fluid was identified in 116 of 191 visits (60.7%). Of these positive visits, the Stratus TD-OCT radial scanning technology demonstrated a significantly lower rate of detection (71.8%) when compared with the Spectralis HRA+OCT spectral domain scanning modalities (radial 87.1%, P < 0.001; 7-line raster 92.0%, P < 0.001; volumetric 94.5%, P < 0.001) or the Cirrus HD-OCT spectral domain scanning modalities (5-line raster 81.6%, P = 0.001; volumetric 92.0%, P < 0.001). Intraretinal cysts and subretinal fluid were identified in 83 visits (43.5%) and 116 visits (60.7%), respectively, with 36 eyes (18.8%) having fluid in both locations. No individual imaging modality demonstrated a diagnostic advantage for detecting subretinal fluid versus intraretinal cysts (e.g., Cirrus volume detected 86.7% of intraretinal cysts and 88.8% of subretinal fluid, P = 0.33).
Conclusion: In this neovascular age-related macular degeneration patient population, spectral-domain ocular coherence tomography was a superior diagnostic tool when compared with TD-OCT, with each spectral domain platform and acquisition setting identifying significantly more exudative disease activity. The two spectral domain platforms (Cirrus and Spectralis) were not directly compared because identical image acquisition parameters were not used. No individual imaging modality demonstrated a diagnostic advantage for detecting subretinal fluid versus intraretinal cysts.