Optical coherence tomography angiography reproducibility of lesion size measurements in neovascular age-related macular degeneration (AMD)

Purpose To evaluate the reproducibility and interuser agreement of measurements of choroidal neovascularisation in optical coherence tomography angiography (OCTA). Design Prospective non-interventional study. Methods Consecutive patients, presenting with neovascular age-related macular degeneration (AMD), underwent two sequential OCTA examinations (AngioVue, Optovue, Fremont, California, USA), performed by the same trained examiner. Neovascular lesion area was then measured on both examinations in the choriocapillaris automatic segmentation by two masked readers, using the semiautomated measuring software embedded in the instrument. Two measuring features were used: the first corresponding to the total manually contoured lesion area with the flow draw tool (select area) and the second to the total area of solely vessels with high flow within the lesion (vessel area). These measurements were then compared in order to assess both the reproducibility of OCTA examination and the interuser agreement with the embedded software. Results Forty-eight eyes of 46 patients (77.4 mean age,+/-8.2SD, range from 62 to 95 years old, eight men, 38 women) were included in our study. Mean choroidal neovascularisation area was of 0.72+/-0.7mm(2) for the first measurement and 0.75+/-0.76mm(2) for the second measurement; difference between the first and the second measurement was 0.03mm(2). Intrauser agreement was of 0.98 (CI 0.98 to 0.99) for both vessel area' and select area' features. Interuser agreement was of 0.98 (CI 0.97 to 0.99) for select area' and vessel area' features. Conclusion Our data suggest that OCTA provide reproducible imaging for evaluation of the neovascular size in the setting of AMD.