Retinoblastoma is diagnosed by examination of the eye under general anesthesia using an ophthalmoscope. Calcifications and vitreous seedings confirm the diagnosis of retinoblastoma. A MRI or CT scan should be done to check for intracranial extension of the disease. Routine bone marrow examination and CSF examination are not indicated except when suspicion of spread of tumor beyond the globe e.g. patients with abnormal CBC or extension of tumor beyond the lamina cribrosa on ophthalmologic examination.