Nadiarnykh O, McNeill-Badalova NA, Gaillard MC, et al. - Researchers conducted this observational study to demonstrate optical coherence tomography (OCT) images of active and inactive retinoblastoma (Rb) tumours. Between November 2010 and October 2017, patients diagnosed with retinoblastoma and retinoma who were presented at Amsterdam UMC and Jules-Gonin Eye Hospital were included. Through discussions by ophthalmologists and physicists, medical records of patients and OCT images were analyzed during meetings. There could be no difference between active and inactive tumours using OCT alone. Handheld OCT, however, adds useful information in monitoring and follow-up of retinoblastoma patients to the established imaging techniques. An overview of OCT images of active and inactive Rbs was provided with this investigation.