<prompt> In retinoblastoma, after enucleation, which tissue is sectioned to find out systemic metastasis-Central retinal aerySclera and episcleraOptic nerveVoex vein  <response>: After enucleation, optic nerve is examined and if it shows tumor invasion, postoperative radiotherapy to the orbital apex and chemotherapy are given. Ref: Khurana 7the p.317. 