In Reply We appreciate the thoughtful comments of Ramanjulu and Palanivelu. We agree that intravenous or intra-arterial chemotherapy can often control vitreous seeds from retinoblastoma. Furthermore, we agree that single-agent intravitreal melphalan can control vitreous seeds in most cases.1- 4 However, a void remains in which single-agent intravitreal chemotherapy has been unsuccessful2 despite multiple injections with increasing or recurrent vitreous malignancy.2 In these cases, we consider 2-agent chemotherapy of melphalan and topotecan. It could be dangerous to inject single-agent therapy in such cases and delay ultimate success, especially if we trust that the previous injection was appropriately performed. Multiple-agent chemotherapy for other cancers is the rule, not the exception.
Ghassemi F, Shields CL, Khodabande A. Is Combination Therapy for Resistant Vitreous Seeds Really Essential?—Reply. JAMA Ophthalmol. 2015;133(2):232-233. doi:10.1001/jamaophthalmol.2014.4657