Fig. 4

Optical coherence tomography (OCT) imaging. a and b OCT B-scans comparing approximately age-matched, a wild-type (WT) d110 and b retinal degenerate (RD) d120 retina. c–e OCT B-scans of retinal organoid tissue transplants in RD rats across treatment and immunocompetence modalities from initial scan, approximately 2 weeks post-surgery (c1-e1), up to 1-month post-surgery (c2–e2), up to final scan near study endpoint. Since the position of the transplant in the eye was variable between surgeries, the optic disc can only be seen in (d1–d3). c1–c3 Transplant to immunodeficient RD rat (Nude TP); d1–d3 transplant to immunocompetent immunosuppressed RD rat (NN TP IS), e1–e3 transplant to immunocompetent non-immunosuppressed RD rat (TP NO IS). Note graft size and integrity is maintained throughout study/observation period for both nude TP and TP IS. Successful immunosuppression mirrors long term graft survival seen in athymic rats with absent T-cells, whereas NN TP NO IS graft is besieged by immune cells at day 34, demonstrated by fuzzy graft appearance and reflective speckles in vitreous (e2). Faced with a competent non-suppressed immune response, this graft is nearly completely consumed by day 70 (e3). Vertical scale bars (red): 100 µm; horizontal scale bars (green): 200 µm