SD-OCT imaging (Bioptigen Envisu R2200; Bioptigen, Research Triangle Park, NC) was used to document and monitor transplant development, as described previously [34, 39] .
Transplanted rats (n=56) were imaged every 1-2 months, starting 2 weeks after surgery, up to 8.9 months of age (7.5 months post-surgery). Rats with transplant misplacement into the vitreous, or excessive surgical trauma were excluded from further analysis. The last scan was scheduled as close as possible to the terminal SC recording. The transplant area was determined by using sequential cross-sectional B-scans to define the host/donor boundary. These positions were then compared to the corresponding locations in the fundus image to outline the transplant (Figure 2 c,f,i). The InVivoVue program (Bioptigen) contains calipers that were used to create several geometric figures to overlay the transplant border.
Transplanted rats (n=56) were imaged every 1-2 months, starting 2 weeks after surgery, up to 8.9 months of age (7.5 months post-surgery). Rats with transplant misplacement into the vitreous, or excessive surgical trauma were excluded from further analysis. The last scan was scheduled as close as possible to the terminal SC recording. The transplant area was determined by using sequential cross-sectional B-scans to define the host/donor boundary. These positions were then compared to the corresponding locations in the fundus image to outline the transplant (Figure 2 c,f,i). The InVivoVue program (Bioptigen) contains calipers that were used to create several geometric figures to overlay the transplant border.