Fig. 1

Photographs and intraoperative OCT (iOCT) images obtained during gene therapy surgery. a–fiOCT image obtained during initial step of subretinal injection with (a, b) unsuccessfully attempted to create the bleb with visible bubbles in the vitreous (color photograph) and incomplete retinal indentation (arrowhead) with blunted needle tip (asterisk) and corresponding shadow of subretinal cannula (arrow). c, d Blunted needle complete indentation/penetration of the retina associated with RPE indentation before successful subretinal injection (red arrowhead), and (d) corresponding shadow of subretinal cannula (arrow). e, f Sharp needle partial indentation/penetration of the retina associated with RPE partial indentation before successful subretinal injection (yellow arrowhead), and corresponding shadow of subretinal cannula (blue arrow)