“…24 In 2014, Munier further described the phenotypic variability of retinoblastoma seeds and classified them into 3 subtypes, namely dust, spheres and clouds. 25 The vitreous seed classification can be predictive in regard to time to regression and number of intravitreal melphalan injections required: median time to regression was 0.6, 1.7, and 7.7 months for dust, spheres, and clouds, respectively, and median number of injections required to reach regression was 3, 5, and 8 injections, respectively. 26 In terms of tumour spread, Smith and Smith performed a systematic review in which they included 14 studies and more than 1,300 intravitreal injections, and concluded it is a rare occurrence.…”