*2.3.3 Ophthalmic ultrasound*

An ophthalmic ultrasound can be performed in the A and B scan mode using a 10 mHz transducer to evaluate for intraocular masses, retinal detachment, or calcification. In retinoblastoma, the ultrasound should reveal an irregular mass, which is more echogenic than the vitreous, and commonly has fine calcifications (highly reflective foci mostly with acoustic shadowing) since upon histologic study, 95% of retinoblastoma contains calcification [14] (**Figure 1**). Measurements should be taken as a baseline to compare to in the future following treatment.
