Spectral-domain versus time domain optical coherence tomography before and after ranibizumab for age-related macular degeneration.

PURPOSE: To study the ability to appreciate qualitative features that indicate disease activity in patients with neovascular age-related macular degeneration (AMD) and to analyze the differences in automated retinal thickness measurement, using 1 time domain optical coherence tomography (TD-OCT) and 2 different spectral-domain OCT (SD-OCT) machines.

METHODS: Thirty-three consecutive naïve patients with neovascular AMD underwent Stratus TD-OCT, Cirrus SD-OCT and Spectralis SD-OCT, at baseline, 1 h, 1 day, 1 week and 1 month after intravitreal ranibizumab injection.

RESULTS: As regards the ability to detect retinal cysts, subretinal fluid and pigment epithelium detachment, at each follow-up visit, there was a significant correlation among all 3 OCT devices (p < 0.05), even though Cirrus SD-OCT and Spectralis SD-OCT showed the highest level of intermachine agreement. At each follow-up visit, automated retinal thickness measurements showed a greater mean central macular thickness (CMT) for both Spectralis SD-OCT and Cirrus SD-OCT, compared with Stratus TD-OCT. However, the mean paired differences in CMT among the 3 OCT devices were not statistically significant (p > 0.05). Overall, Cirrus SD-CT showed fewer segmentation errors, compared with both Spectralis SD-OCT and Stratus TD-OCT.

CONCLUSION: SD-OCT showed a greater ability to evaluate qualitative features indicating disease activity and fewer errors in automated segmentation. However, differences in CMT changes were similar between TD-OCT and SD-OCT systems during follow-up.